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7<header class="hero"><span class="badge">PYTHON 3 MEGA REFERENCE</span><h1>Python<br>Cheat Sheet</h1><p>A huge searchable, copy-ready Python 3 reference covering syntax, collections, functions, OOP, files, JSON, regex, typing, async, testing, SQLite, CLI tools, and more.</p><div class="stats"><div class="stat"><b>409</b> snippets</div><div class="stat"><b>28</b> sections</div><div class="stat"><b>1</b> standalone HTML file</div></div></header>
8<div class="toolbar"><div class="toolbarin"><input id="search" type="search" placeholder="Search Python syntax, libraries, snippets, or topics…"><button class="toolbtn" id="expand">Expand All</button><button class="toolbtn" id="collapse">Collapse All</button></div></div>
9<div class="note"><div class="notebox"><b>Python note:</b> This targets modern Python 3. Optional third-party tools such as Requests, Black, and Ruff must be installed separately.</div></div>
10<div class="layout"><nav><strong>JUMP TO SECTION</strong><a href="#basics---variables">Basics &amp; Variables</a><a href="#operators---numbers">Operators &amp; Numbers</a><a href="#strings">Strings</a><a href="#lists">Lists</a><a href="#tuples--sets---dicts">Tuples, Sets &amp; Dicts</a><a href="#conditionals---loops">Conditionals &amp; Loops</a><a href="#comprehensions">Comprehensions</a><a href="#functions">Functions</a><a href="#oop---classes">Oop &amp; Classes</a><a href="#exceptions">Exceptions</a><a href="#files---pathlib">Files &amp; Pathlib</a><a href="#json---csv">Json &amp; Csv</a><a href="#datetime---time">Datetime &amp; Time</a><a href="#regex">Regex</a><a href="#math---random">Math &amp; Random</a><a href="#iterators---generators">Iterators &amp; Generators</a><a href="#modules--venv---pip">Modules, Venv &amp; Pip</a><a href="#typing---dataclasses">Typing &amp; Dataclasses</a><a href="#os--sys---subprocess">Os, Sys &amp; Subprocess</a><a href="#collections---functools">Collections &amp; Functools</a><a href="#logging---cli">Logging &amp; Cli</a><a href="#asyncio---concurrency">Asyncio &amp; Concurrency</a><a href="#sqlite">Sqlite</a><a href="#testing">Testing</a><a href="#http-requests---third-party">Http Requests — Third Party</a><a href="#useful-built-ins---one-liners">Useful Built-Ins &amp; One-Liners</a><a href="#common-pitfalls">Common Pitfalls</a><a href="#formatting---code-quality">Formatting &amp; Code Quality</a></nav><main><section class="section" id="basics---variables"><button class="sectionhead"><span>Basics &amp; Variables</span><small>19 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="basics &amp; variables print(&#x27;hello, world!&#x27;) print output"><div class="cmdrow"><pre><code>print(&#x27;Hello, world!&#x27;)</code></pre><button class="copy" data-copy="print(&#x27;Hello, world!&#x27;)">COPY</button></div><p>Print output</p></article><article class="card" data-search="basics &amp; variables name = &#x27;ada&#x27; assign a string"><div class="cmdrow"><pre><code>name = &#x27;Ada&#x27;</code></pre><button class="copy" data-copy="name = &#x27;Ada&#x27;">COPY</button></div><p>Assign a string</p></article><article class="card" data-search="basics &amp; variables age = 18 assign an integer"><div class="cmdrow"><pre><code>age = 18</code></pre><button class="copy" data-copy="age = 18">COPY</button></div><p>Assign an integer</p></article><article class="card" data-search="basics &amp; variables price = 19.99 assign a float"><div class="cmdrow"><pre><code>price = 19.99</code></pre><button class="copy" data-copy="price = 19.99">COPY</button></div><p>Assign a float</p></article><article class="card" data-search="basics &amp; variables active = true assign a boolean"><div class="cmdrow"><pre><code>active = True</code></pre><button class="copy" data-copy="active = True">COPY</button></div><p>Assign a boolean</p></article><article class="card" data-search="basics &amp; variables value = none represent no value"><div class="cmdrow"><pre><code>value = None</code></pre><button class="copy" data-copy="value = None">COPY</button></div><p>Represent no value</p></article><article class="card" data-search="basics &amp; variables x, y = 10, 20 multiple assignment"><div class="cmdrow"><pre><code>x, y = 10, 20</code></pre><button class="copy" data-copy="x, y = 10, 20">COPY</button></div><p>Multiple assignment</p></article><article class="card" data-search="basics &amp; variables x, y = y, x swap values"><div class="cmdrow"><pre><code>x, y = y, x</code></pre><button class="copy" data-copy="x, y = y, x">COPY</button></div><p>Swap values</p></article><article class="card" data-search="basics &amp; variables a = b = 0 assign one value to multiple names"><div class="cmdrow"><pre><code>a = b = 0</code></pre><button class="copy" data-copy="a = b = 0">COPY</button></div><p>Assign one value to multiple names</p></article><article class="card" data-search="basics &amp; variables type(value) return an object&#x27;s type"><div class="cmdrow"><pre><code>type(value)</code></pre><button class="copy" data-copy="type(value)">COPY</button></div><p>Return an object&#x27;s type</p></article><article class="card" data-search="basics &amp; variables isinstance(value, int) check an object&#x27;s type"><div class="cmdrow"><pre><code>isinstance(value, int)</code></pre><button class="copy" data-copy="isinstance(value, int)">COPY</button></div><p>Check an object&#x27;s type</p></article><article class="card" data-search="basics &amp; variables id(value) return object identity"><div class="cmdrow"><pre><code>id(value)</code></pre><button class="copy" data-copy="id(value)">COPY</button></div><p>Return object identity</p></article><article class="card" data-search="basics &amp; variables input(&#x27;name: &#x27;) read keyboard input"><div class="cmdrow"><pre><code>input(&#x27;Name: &#x27;)</code></pre><button class="copy" data-copy="input(&#x27;Name: &#x27;)">COPY</button></div><p>Read keyboard input</p></article><article class="card" data-search="basics &amp; variables int(&#x27;42&#x27;) convert text to integer"><div class="cmdrow"><pre><code>int(&#x27;42&#x27;)</code></pre><button class="copy" data-copy="int(&#x27;42&#x27;)">COPY</button></div><p>Convert text to integer</p></article><article class="card" data-search="basics &amp; variables float(&#x27;3.14&#x27;) convert text to float"><div class="cmdrow"><pre><code>float(&#x27;3.14&#x27;)</code></pre><button class="copy" data-copy="float(&#x27;3.14&#x27;)">COPY</button></div><p>Convert text to float</p></article><article class="card" data-search="basics &amp; variables str(123) convert a value to text"><div class="cmdrow"><pre><code>str(123)</code></pre><button class="copy" data-copy="str(123)">COPY</button></div><p>Convert a value to text</p></article><article class="card" data-search="basics &amp; variables bool(value) convert a value to boolean"><div class="cmdrow"><pre><code>bool(value)</code></pre><button class="copy" data-copy="bool(value)">COPY</button></div><p>Convert a value to boolean</p></article><article class="card" data-search="basics &amp; variables help(str) open built-in documentation"><div class="cmdrow"><pre><code>help(str)</code></pre><button class="copy" data-copy="help(str)">COPY</button></div><p>Open built-in documentation</p></article><article class="card" data-search="basics &amp; variables dir(object) list available attributes"><div class="cmdrow"><pre><code>dir(object)</code></pre><button class="copy" data-copy="dir(object)">COPY</button></div><p>List available attributes</p></article></div></div></section><section class="section" id="operators---numbers"><button class="sectionhead"><span>Operators &amp; Numbers</span><small>24 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="operators &amp; numbers 7 + 3 addition"><div class="cmdrow"><pre><code>7 + 3</code></pre><button class="copy" data-copy="7 + 3">COPY</button></div><p>Addition</p></article><article class="card" data-search="operators &amp; numbers 7 - 3 subtraction"><div class="cmdrow"><pre><code>7 - 3</code></pre><button class="copy" data-copy="7 - 3">COPY</button></div><p>Subtraction</p></article><article class="card" data-search="operators &amp; numbers 7 * 3 multiplication"><div class="cmdrow"><pre><code>7 * 3</code></pre><button class="copy" data-copy="7 * 3">COPY</button></div><p>Multiplication</p></article><article class="card" data-search="operators &amp; numbers 7 / 3 floating-point division"><div class="cmdrow"><pre><code>7 / 3</code></pre><button class="copy" data-copy="7 / 3">COPY</button></div><p>Floating-point division</p></article><article class="card" data-search="operators &amp; numbers 7 // 3 floor division"><div class="cmdrow"><pre><code>7 // 3</code></pre><button class="copy" data-copy="7 // 3">COPY</button></div><p>Floor division</p></article><article class="card" data-search="operators &amp; numbers 7 % 3 remainder / modulo"><div class="cmdrow"><pre><code>7 % 3</code></pre><button class="copy" data-copy="7 % 3">COPY</button></div><p>Remainder / modulo</p></article><article class="card" data-search="operators &amp; numbers 7 ** 3 exponentiation"><div class="cmdrow"><pre><code>7 ** 3</code></pre><button class="copy" data-copy="7 ** 3">COPY</button></div><p>Exponentiation</p></article><article class="card" data-search="operators &amp; numbers abs(-8) absolute value"><div class="cmdrow"><pre><code>abs(-8)</code></pre><button class="copy" data-copy="abs(-8)">COPY</button></div><p>Absolute value</p></article><article class="card" data-search="operators &amp; numbers round(3.14159, 2) round to two decimal places"><div class="cmdrow"><pre><code>round(3.14159, 2)</code></pre><button class="copy" data-copy="round(3.14159, 2)">COPY</button></div><p>Round to two decimal places</p></article><article class="card" data-search="operators &amp; numbers min(4, 2, 9) minimum"><div class="cmdrow"><pre><code>min(4, 2, 9)</code></pre><button class="copy" data-copy="min(4, 2, 9)">COPY</button></div><p>Minimum</p></article><article class="card" data-search="operators &amp; numbers max(4, 2, 9) maximum"><div class="cmdrow"><pre><code>max(4, 2, 9)</code></pre><button class="copy" data-copy="max(4, 2, 9)">COPY</button></div><p>Maximum</p></article><article class="card" data-search="operators &amp; numbers sum([1, 2, 3]) sum values"><div class="cmdrow"><pre><code>sum([1, 2, 3])</code></pre><button class="copy" data-copy="sum([1, 2, 3])">COPY</button></div><p>Sum values</p></article><article class="card" data-search="operators &amp; numbers divmod(17, 5) return quotient and remainder"><div class="cmdrow"><pre><code>divmod(17, 5)</code></pre><button class="copy" data-copy="divmod(17, 5)">COPY</button></div><p>Return quotient and remainder</p></article><article class="card" data-search="operators &amp; numbers pow(2, 8) raise to a power"><div class="cmdrow"><pre><code>pow(2, 8)</code></pre><button class="copy" data-copy="pow(2, 8)">COPY</button></div><p>Raise to a power</p></article><article class="card" data-search="operators &amp; numbers x += 1 increment"><div class="cmdrow"><pre><code>x += 1</code></pre><button class="copy" data-copy="x += 1">COPY</button></div><p>Increment</p></article><article class="card" data-search="operators &amp; numbers x -= 1 decrement"><div class="cmdrow"><pre><code>x -= 1</code></pre><button class="copy" data-copy="x -= 1">COPY</button></div><p>Decrement</p></article><article class="card" data-search="operators &amp; numbers x *= 2 multiply and assign"><div class="cmdrow"><pre><code>x *= 2</code></pre><button class="copy" data-copy="x *= 2">COPY</button></div><p>Multiply and assign</p></article><article class="card" data-search="operators &amp; numbers x /= 2 divide and assign"><div class="cmdrow"><pre><code>x /= 2</code></pre><button class="copy" data-copy="x /= 2">COPY</button></div><p>Divide and assign</p></article><article class="card" data-search="operators &amp; numbers a == b equality comparison"><div class="cmdrow"><pre><code>a == b</code></pre><button class="copy" data-copy="a == b">COPY</button></div><p>Equality comparison</p></article><article class="card" data-search="operators &amp; numbers a != b inequality comparison"><div class="cmdrow"><pre><code>a != b</code></pre><button class="copy" data-copy="a != b">COPY</button></div><p>Inequality comparison</p></article><article class="card" data-search="operators &amp; numbers a &lt; b &lt;= c chained comparison"><div class="cmdrow"><pre><code>a &lt; b &lt;= c</code></pre><button class="copy" data-copy="a &lt; b &lt;= c">COPY</button></div><p>Chained comparison</p></article><article class="card" data-search="operators &amp; numbers a and b logical and"><div class="cmdrow"><pre><code>a and b</code></pre><button class="copy" data-copy="a and b">COPY</button></div><p>Logical AND</p></article><article class="card" data-search="operators &amp; numbers a or b logical or"><div class="cmdrow"><pre><code>a or b</code></pre><button class="copy" data-copy="a or b">COPY</button></div><p>Logical OR</p></article><article class="card" data-search="operators &amp; numbers not a logical not"><div class="cmdrow"><pre><code>not a</code></pre><button class="copy" data-copy="not a">COPY</button></div><p>Logical NOT</p></article></div></div></section><section class="section" id="strings"><button class="sectionhead"><span>Strings</span><small>28 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="strings text = &#x27;hello&#x27; create a string"><div class="cmdrow"><pre><code>text = &#x27;hello&#x27;</code></pre><button class="copy" data-copy="text = &#x27;hello&#x27;">COPY</button></div><p>Create a string</p></article><article class="card" data-search="strings text = &quot;hello&quot; double-quoted string"><div class="cmdrow"><pre><code>text = &quot;hello&quot;</code></pre><button class="copy" data-copy="text = &quot;hello&quot;">COPY</button></div><p>Double-quoted string</p></article><article class="card" data-search="strings text = &#x27;&#x27;&#x27;multi
11line&#x27;&#x27;&#x27; multiline string"><div class="cmdrow"><pre><code>text = &#x27;&#x27;&#x27;multi
12line&#x27;&#x27;&#x27;</code></pre><button class="copy" data-copy="text = &#x27;&#x27;&#x27;multi
13line&#x27;&#x27;&#x27;">COPY</button></div><p>Multiline string</p></article><article class="card" data-search="strings text[0] first character"><div class="cmdrow"><pre><code>text[0]</code></pre><button class="copy" data-copy="text[0]">COPY</button></div><p>First character</p></article><article class="card" data-search="strings text[-1] last character"><div class="cmdrow"><pre><code>text[-1]</code></pre><button class="copy" data-copy="text[-1]">COPY</button></div><p>Last character</p></article><article class="card" data-search="strings text[1:4] slice a string"><div class="cmdrow"><pre><code>text[1:4]</code></pre><button class="copy" data-copy="text[1:4]">COPY</button></div><p>Slice a string</p></article><article class="card" data-search="strings text[::-1] reverse a string"><div class="cmdrow"><pre><code>text[::-1]</code></pre><button class="copy" data-copy="text[::-1]">COPY</button></div><p>Reverse a string</p></article><article class="card" data-search="strings len(text) string length"><div class="cmdrow"><pre><code>len(text)</code></pre><button class="copy" data-copy="len(text)">COPY</button></div><p>String length</p></article><article class="card" data-search="strings text.upper() uppercase"><div class="cmdrow"><pre><code>text.upper()</code></pre><button class="copy" data-copy="text.upper()">COPY</button></div><p>Uppercase</p></article><article class="card" data-search="strings text.lower() lowercase"><div class="cmdrow"><pre><code>text.lower()</code></pre><button class="copy" data-copy="text.lower()">COPY</button></div><p>Lowercase</p></article><article class="card" data-search="strings text.title() title case"><div class="cmdrow"><pre><code>text.title()</code></pre><button class="copy" data-copy="text.title()">COPY</button></div><p>Title case</p></article><article class="card" data-search="strings text.capitalize() capitalize first character"><div class="cmdrow"><pre><code>text.capitalize()</code></pre><button class="copy" data-copy="text.capitalize()">COPY</button></div><p>Capitalize first character</p></article><article class="card" data-search="strings text.strip() trim outer whitespace"><div class="cmdrow"><pre><code>text.strip()</code></pre><button class="copy" data-copy="text.strip()">COPY</button></div><p>Trim outer whitespace</p></article><article class="card" data-search="strings text.lstrip() trim left whitespace"><div class="cmdrow"><pre><code>text.lstrip()</code></pre><button class="copy" data-copy="text.lstrip()">COPY</button></div><p>Trim left whitespace</p></article><article class="card" data-search="strings text.rstrip() trim right whitespace"><div class="cmdrow"><pre><code>text.rstrip()</code></pre><button class="copy" data-copy="text.rstrip()">COPY</button></div><p>Trim right whitespace</p></article><article class="card" data-search="strings text.replace(&#x27;old&#x27;, &#x27;new&#x27;) replace text"><div class="cmdrow"><pre><code>text.replace(&#x27;old&#x27;, &#x27;new&#x27;)</code></pre><button class="copy" data-copy="text.replace(&#x27;old&#x27;, &#x27;new&#x27;)">COPY</button></div><p>Replace text</p></article><article class="card" data-search="strings text.split(&#x27;,&#x27;) split into a list"><div class="cmdrow"><pre><code>text.split(&#x27;,&#x27;)</code></pre><button class="copy" data-copy="text.split(&#x27;,&#x27;)">COPY</button></div><p>Split into a list</p></article><article class="card" data-search="strings &#x27;,&#x27;.join(items) join strings"><div class="cmdrow"><pre><code>&#x27;,&#x27;.join(items)</code></pre><button class="copy" data-copy="&#x27;,&#x27;.join(items)">COPY</button></div><p>Join strings</p></article><article class="card" data-search="strings text.startswith(&#x27;pre&#x27;) test prefix"><div class="cmdrow"><pre><code>text.startswith(&#x27;pre&#x27;)</code></pre><button class="copy" data-copy="text.startswith(&#x27;pre&#x27;)">COPY</button></div><p>Test prefix</p></article><article class="card" data-search="strings text.endswith(&#x27;.txt&#x27;) test suffix"><div class="cmdrow"><pre><code>text.endswith(&#x27;.txt&#x27;)</code></pre><button class="copy" data-copy="text.endswith(&#x27;.txt&#x27;)">COPY</button></div><p>Test suffix</p></article><article class="card" data-search="strings &#x27;cat&#x27; in text check substring membership"><div class="cmdrow"><pre><code>&#x27;cat&#x27; in text</code></pre><button class="copy" data-copy="&#x27;cat&#x27; in text">COPY</button></div><p>Check substring membership</p></article><article class="card" data-search="strings text.find(&#x27;cat&#x27;) find substring index"><div class="cmdrow"><pre><code>text.find(&#x27;cat&#x27;)</code></pre><button class="copy" data-copy="text.find(&#x27;cat&#x27;)">COPY</button></div><p>Find substring index</p></article><article class="card" data-search="strings text.count(&#x27;a&#x27;) count occurrences"><div class="cmdrow"><pre><code>text.count(&#x27;a&#x27;)</code></pre><button class="copy" data-copy="text.count(&#x27;a&#x27;)">COPY</button></div><p>Count occurrences</p></article><article class="card" data-search="strings f&#x27;hello {name}&#x27; basic f-string"><div class="cmdrow"><pre><code>f&#x27;Hello {name}&#x27;</code></pre><button class="copy" data-copy="f&#x27;Hello {name}&#x27;">COPY</button></div><p>Basic f-string</p></article><article class="card" data-search="strings f&#x27;{price:.2f}&#x27; format decimal places"><div class="cmdrow"><pre><code>f&#x27;{price:.2f}&#x27;</code></pre><button class="copy" data-copy="f&#x27;{price:.2f}&#x27;">COPY</button></div><p>Format decimal places</p></article><article class="card" data-search="strings f&#x27;{value:&gt;10}&#x27; right-align in a field"><div class="cmdrow"><pre><code>f&#x27;{value:&gt;10}&#x27;</code></pre><button class="copy" data-copy="f&#x27;{value:&gt;10}&#x27;">COPY</button></div><p>Right-align in a field</p></article><article class="card" data-search="strings f&#x27;{number:,}&#x27; add thousands separators"><div class="cmdrow"><pre><code>f&#x27;{number:,}&#x27;</code></pre><button class="copy" data-copy="f&#x27;{number:,}&#x27;">COPY</button></div><p>Add thousands separators</p></article><article class="card" data-search="strings repr(text) developer-facing representation"><div class="cmdrow"><pre><code>repr(text)</code></pre><button class="copy" data-copy="repr(text)">COPY</button></div><p>Developer-facing representation</p></article></div></div></section><section class="section" id="lists"><button class="sectionhead"><span>Lists</span><small>23 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="lists items = [1, 2, 3] create a list"><div class="cmdrow"><pre><code>items = [1, 2, 3]</code></pre><button class="copy" data-copy="items = [1, 2, 3]">COPY</button></div><p>Create a list</p></article><article class="card" data-search="lists items[0] first item"><div class="cmdrow"><pre><code>items[0]</code></pre><button class="copy" data-copy="items[0]">COPY</button></div><p>First item</p></article><article class="card" data-search="lists items[-1] last item"><div class="cmdrow"><pre><code>items[-1]</code></pre><button class="copy" data-copy="items[-1]">COPY</button></div><p>Last item</p></article><article class="card" data-search="lists items[1:4] slice a list"><div class="cmdrow"><pre><code>items[1:4]</code></pre><button class="copy" data-copy="items[1:4]">COPY</button></div><p>Slice a list</p></article><article class="card" data-search="lists items.append(4) append one item"><div class="cmdrow"><pre><code>items.append(4)</code></pre><button class="copy" data-copy="items.append(4)">COPY</button></div><p>Append one item</p></article><article class="card" data-search="lists items.extend([4, 5]) append multiple items"><div class="cmdrow"><pre><code>items.extend([4, 5])</code></pre><button class="copy" data-copy="items.extend([4, 5])">COPY</button></div><p>Append multiple items</p></article><article class="card" data-search="lists items.insert(1, &#x27;x&#x27;) insert at index"><div class="cmdrow"><pre><code>items.insert(1, &#x27;x&#x27;)</code></pre><button class="copy" data-copy="items.insert(1, &#x27;x&#x27;)">COPY</button></div><p>Insert at index</p></article><article class="card" data-search="lists items.remove(&#x27;x&#x27;) remove first matching value"><div class="cmdrow"><pre><code>items.remove(&#x27;x&#x27;)</code></pre><button class="copy" data-copy="items.remove(&#x27;x&#x27;)">COPY</button></div><p>Remove first matching value</p></article><article class="card" data-search="lists items.pop() remove and return last item"><div class="cmdrow"><pre><code>items.pop()</code></pre><button class="copy" data-copy="items.pop()">COPY</button></div><p>Remove and return last item</p></article><article class="card" data-search="lists items.pop(0) remove and return by index"><div class="cmdrow"><pre><code>items.pop(0)</code></pre><button class="copy" data-copy="items.pop(0)">COPY</button></div><p>Remove and return by index</p></article><article class="card" data-search="lists items.clear() remove all items"><div class="cmdrow"><pre><code>items.clear()</code></pre><button class="copy" data-copy="items.clear()">COPY</button></div><p>Remove all items</p></article><article class="card" data-search="lists items.index(&#x27;x&#x27;) find index"><div class="cmdrow"><pre><code>items.index(&#x27;x&#x27;)</code></pre><button class="copy" data-copy="items.index(&#x27;x&#x27;)">COPY</button></div><p>Find index</p></article><article class="card" data-search="lists items.count(&#x27;x&#x27;) count values"><div class="cmdrow"><pre><code>items.count(&#x27;x&#x27;)</code></pre><button class="copy" data-copy="items.count(&#x27;x&#x27;)">COPY</button></div><p>Count values</p></article><article class="card" data-search="lists items.sort() sort in place"><div class="cmdrow"><pre><code>items.sort()</code></pre><button class="copy" data-copy="items.sort()">COPY</button></div><p>Sort in place</p></article><article class="card" data-search="lists items.sort(reverse=true) sort descending"><div class="cmdrow"><pre><code>items.sort(reverse=True)</code></pre><button class="copy" data-copy="items.sort(reverse=True)">COPY</button></div><p>Sort descending</p></article><article class="card" data-search="lists sorted(items) return a sorted copy"><div class="cmdrow"><pre><code>sorted(items)</code></pre><button class="copy" data-copy="sorted(items)">COPY</button></div><p>Return a sorted copy</p></article><article class="card" data-search="lists items.reverse() reverse in place"><div class="cmdrow"><pre><code>items.reverse()</code></pre><button class="copy" data-copy="items.reverse()">COPY</button></div><p>Reverse in place</p></article><article class="card" data-search="lists list(reversed(items)) return a reversed list"><div class="cmdrow"><pre><code>list(reversed(items))</code></pre><button class="copy" data-copy="list(reversed(items))">COPY</button></div><p>Return a reversed list</p></article><article class="card" data-search="lists items.copy() shallow-copy a list"><div class="cmdrow"><pre><code>items.copy()</code></pre><button class="copy" data-copy="items.copy()">COPY</button></div><p>Shallow-copy a list</p></article><article class="card" data-search="lists len(items) list length"><div class="cmdrow"><pre><code>len(items)</code></pre><button class="copy" data-copy="len(items)">COPY</button></div><p>List length</p></article><article class="card" data-search="lists &#x27;x&#x27; in items membership test"><div class="cmdrow"><pre><code>&#x27;x&#x27; in items</code></pre><button class="copy" data-copy="&#x27;x&#x27; in items">COPY</button></div><p>Membership test</p></article><article class="card" data-search="lists items + other concatenate lists"><div class="cmdrow"><pre><code>items + other</code></pre><button class="copy" data-copy="items + other">COPY</button></div><p>Concatenate lists</p></article><article class="card" data-search="lists items * 3 repeat a list"><div class="cmdrow"><pre><code>items * 3</code></pre><button class="copy" data-copy="items * 3">COPY</button></div><p>Repeat a list</p></article></div></div></section><section class="section" id="tuples--sets---dicts"><button class="sectionhead"><span>Tuples, Sets &amp; Dicts</span><small>23 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="tuples, sets &amp; dicts point = (10, 20) create a tuple"><div class="cmdrow"><pre><code>point = (10, 20)</code></pre><button class="copy" data-copy="point = (10, 20)">COPY</button></div><p>Create a tuple</p></article><article class="card" data-search="tuples, sets &amp; dicts x, y = point unpack a tuple"><div class="cmdrow"><pre><code>x, y = point</code></pre><button class="copy" data-copy="x, y = point">COPY</button></div><p>Unpack a tuple</p></article><article class="card" data-search="tuples, sets &amp; dicts single = (42,) one-item tuple"><div class="cmdrow"><pre><code>single = (42,)</code></pre><button class="copy" data-copy="single = (42,)">COPY</button></div><p>One-item tuple</p></article><article class="card" data-search="tuples, sets &amp; dicts colors = {&#x27;red&#x27;, &#x27;green&#x27;} create a set"><div class="cmdrow"><pre><code>colors = {&#x27;red&#x27;, &#x27;green&#x27;}</code></pre><button class="copy" data-copy="colors = {&#x27;red&#x27;, &#x27;green&#x27;}">COPY</button></div><p>Create a set</p></article><article class="card" data-search="tuples, sets &amp; dicts set([1, 1, 2]) remove duplicates"><div class="cmdrow"><pre><code>set([1, 1, 2])</code></pre><button class="copy" data-copy="set([1, 1, 2])">COPY</button></div><p>Remove duplicates</p></article><article class="card" data-search="tuples, sets &amp; dicts colors.add(&#x27;blue&#x27;) add to a set"><div class="cmdrow"><pre><code>colors.add(&#x27;blue&#x27;)</code></pre><button class="copy" data-copy="colors.add(&#x27;blue&#x27;)">COPY</button></div><p>Add to a set</p></article><article class="card" data-search="tuples, sets &amp; dicts colors.remove(&#x27;red&#x27;) remove or raise if missing"><div class="cmdrow"><pre><code>colors.remove(&#x27;red&#x27;)</code></pre><button class="copy" data-copy="colors.remove(&#x27;red&#x27;)">COPY</button></div><p>Remove or raise if missing</p></article><article class="card" data-search="tuples, sets &amp; dicts colors.discard(&#x27;red&#x27;) remove safely if present"><div class="cmdrow"><pre><code>colors.discard(&#x27;red&#x27;)</code></pre><button class="copy" data-copy="colors.discard(&#x27;red&#x27;)">COPY</button></div><p>Remove safely if present</p></article><article class="card" data-search="tuples, sets &amp; dicts a b|set union"><div class="cmdrow"><pre><code>a </code></pre><button class="copy" data-copy="a ">COPY</button></div><p> b|Set union</p></article><article class="card" data-search="tuples, sets &amp; dicts a &amp; b set intersection"><div class="cmdrow"><pre><code>a &amp; b</code></pre><button class="copy" data-copy="a &amp; b">COPY</button></div><p>Set intersection</p></article><article class="card" data-search="tuples, sets &amp; dicts a - b set difference"><div class="cmdrow"><pre><code>a - b</code></pre><button class="copy" data-copy="a - b">COPY</button></div><p>Set difference</p></article><article class="card" data-search="tuples, sets &amp; dicts a ^ b set symmetric difference"><div class="cmdrow"><pre><code>a ^ b</code></pre><button class="copy" data-copy="a ^ b">COPY</button></div><p>Set symmetric difference</p></article><article class="card" data-search="tuples, sets &amp; dicts user = {&#x27;name&#x27;: &#x27;ada&#x27;, &#x27;age&#x27;: 18} create a dictionary"><div class="cmdrow"><pre><code>user = {&#x27;name&#x27;: &#x27;Ada&#x27;, &#x27;age&#x27;: 18}</code></pre><button class="copy" data-copy="user = {&#x27;name&#x27;: &#x27;Ada&#x27;, &#x27;age&#x27;: 18}">COPY</button></div><p>Create a dictionary</p></article><article class="card" data-search="tuples, sets &amp; dicts user[&#x27;name&#x27;] read a dictionary value"><div class="cmdrow"><pre><code>user[&#x27;name&#x27;]</code></pre><button class="copy" data-copy="user[&#x27;name&#x27;]">COPY</button></div><p>Read a dictionary value</p></article><article class="card" data-search="tuples, sets &amp; dicts user.get(&#x27;email&#x27;) read safely"><div class="cmdrow"><pre><code>user.get(&#x27;email&#x27;)</code></pre><button class="copy" data-copy="user.get(&#x27;email&#x27;)">COPY</button></div><p>Read safely</p></article><article class="card" data-search="tuples, sets &amp; dicts user.get(&#x27;email&#x27;, &#x27;n/a&#x27;) read with default"><div class="cmdrow"><pre><code>user.get(&#x27;email&#x27;, &#x27;n/a&#x27;)</code></pre><button class="copy" data-copy="user.get(&#x27;email&#x27;, &#x27;n/a&#x27;)">COPY</button></div><p>Read with default</p></article><article class="card" data-search="tuples, sets &amp; dicts user[&#x27;email&#x27;] = &#x27;[email protected]&#x27; add or update key"><div class="cmdrow"><pre><code>user[&#x27;email&#x27;] = &#x27;[email protected]&#x27;</code></pre><button class="copy" data-copy="user[&#x27;email&#x27;] = &#x27;[email protected]&#x27;">COPY</button></div><p>Add or update key</p></article><article class="card" data-search="tuples, sets &amp; dicts user.update({&#x27;age&#x27;: 19}) update multiple keys"><div class="cmdrow"><pre><code>user.update({&#x27;age&#x27;: 19})</code></pre><button class="copy" data-copy="user.update({&#x27;age&#x27;: 19})">COPY</button></div><p>Update multiple keys</p></article><article class="card" data-search="tuples, sets &amp; dicts user.pop(&#x27;age&#x27;) remove and return a key"><div class="cmdrow"><pre><code>user.pop(&#x27;age&#x27;)</code></pre><button class="copy" data-copy="user.pop(&#x27;age&#x27;)">COPY</button></div><p>Remove and return a key</p></article><article class="card" data-search="tuples, sets &amp; dicts user.keys() dictionary keys"><div class="cmdrow"><pre><code>user.keys()</code></pre><button class="copy" data-copy="user.keys()">COPY</button></div><p>Dictionary keys</p></article><article class="card" data-search="tuples, sets &amp; dicts user.values() dictionary values"><div class="cmdrow"><pre><code>user.values()</code></pre><button class="copy" data-copy="user.values()">COPY</button></div><p>Dictionary values</p></article><article class="card" data-search="tuples, sets &amp; dicts user.items() key/value pairs"><div class="cmdrow"><pre><code>user.items()</code></pre><button class="copy" data-copy="user.items()">COPY</button></div><p>Key/value pairs</p></article><article class="card" data-search="tuples, sets &amp; dicts &#x27;name&#x27; in user check whether key exists"><div class="cmdrow"><pre><code>&#x27;name&#x27; in user</code></pre><button class="copy" data-copy="&#x27;name&#x27; in user">COPY</button></div><p>Check whether key exists</p></article></div></div></section><section class="section" id="conditionals---loops"><button class="sectionhead"><span>Conditionals &amp; Loops</span><small>16 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="conditionals &amp; loops if x &gt; 0:
14 print(&#x27;positive&#x27;) basic if statement"><div class="cmdrow"><pre><code>if x &gt; 0:
15 print(&#x27;positive&#x27;)</code></pre><button class="copy" data-copy="if x &gt; 0:
16 print(&#x27;positive&#x27;)">COPY</button></div><p>Basic if statement</p></article><article class="card" data-search="conditionals &amp; loops if x &gt; 0:
17 print(&#x27;positive&#x27;)
18else:
19 print(&#x27;other&#x27;) if / else"><div class="cmdrow"><pre><code>if x &gt; 0:
20 print(&#x27;positive&#x27;)
21else:
22 print(&#x27;other&#x27;)</code></pre><button class="copy" data-copy="if x &gt; 0:
23 print(&#x27;positive&#x27;)
24else:
25 print(&#x27;other&#x27;)">COPY</button></div><p>if / else</p></article><article class="card" data-search="conditionals &amp; loops if x &gt; 0:
26 ...
27elif x == 0:
28 ...
29else:
30 ... if / elif / else"><div class="cmdrow"><pre><code>if x &gt; 0:
31 ...
32elif x == 0:
33 ...
34else:
35 ...</code></pre><button class="copy" data-copy="if x &gt; 0:
36 ...
37elif x == 0:
38 ...
39else:
40 ...">COPY</button></div><p>if / elif / else</p></article><article class="card" data-search="conditionals &amp; loops status = &#x27;adult&#x27; if age &gt;= 18 else &#x27;minor&#x27; conditional expression"><div class="cmdrow"><pre><code>status = &#x27;adult&#x27; if age &gt;= 18 else &#x27;minor&#x27;</code></pre><button class="copy" data-copy="status = &#x27;adult&#x27; if age &gt;= 18 else &#x27;minor&#x27;">COPY</button></div><p>Conditional expression</p></article><article class="card" data-search="conditionals &amp; loops if value is none:
41 ... check for none"><div class="cmdrow"><pre><code>if value is None:
42 ...</code></pre><button class="copy" data-copy="if value is None:
43 ...">COPY</button></div><p>Check for None</p></article><article class="card" data-search="conditionals &amp; loops if not items:
44 ... check for empty or falsy value"><div class="cmdrow"><pre><code>if not items:
45 ...</code></pre><button class="copy" data-copy="if not items:
46 ...">COPY</button></div><p>Check for empty or falsy value</p></article><article class="card" data-search="conditionals &amp; loops if 1 &lt;= x &lt;= 10:
47 ... range check"><div class="cmdrow"><pre><code>if 1 &lt;= x &lt;= 10:
48 ...</code></pre><button class="copy" data-copy="if 1 &lt;= x &lt;= 10:
49 ...">COPY</button></div><p>Range check</p></article><article class="card" data-search="conditionals &amp; loops for item in items:
50 print(item) loop over items"><div class="cmdrow"><pre><code>for item in items:
51 print(item)</code></pre><button class="copy" data-copy="for item in items:
52 print(item)">COPY</button></div><p>Loop over items</p></article><article class="card" data-search="conditionals &amp; loops for i in range(5):
53 print(i) loop from 0 to 4"><div class="cmdrow"><pre><code>for i in range(5):
54 print(i)</code></pre><button class="copy" data-copy="for i in range(5):
55 print(i)">COPY</button></div><p>Loop from 0 to 4</p></article><article class="card" data-search="conditionals &amp; loops for i in range(2, 10, 2):
56 print(i) loop with start stop step"><div class="cmdrow"><pre><code>for i in range(2, 10, 2):
57 print(i)</code></pre><button class="copy" data-copy="for i in range(2, 10, 2):
58 print(i)">COPY</button></div><p>Loop with start stop step</p></article><article class="card" data-search="conditionals &amp; loops for i, item in enumerate(items):
59 print(i, item) loop with indexes"><div class="cmdrow"><pre><code>for i, item in enumerate(items):
60 print(i, item)</code></pre><button class="copy" data-copy="for i, item in enumerate(items):
61 print(i, item)">COPY</button></div><p>Loop with indexes</p></article><article class="card" data-search="conditionals &amp; loops for a, b in zip(xs, ys):
62 print(a, b) loop over two iterables"><div class="cmdrow"><pre><code>for a, b in zip(xs, ys):
63 print(a, b)</code></pre><button class="copy" data-copy="for a, b in zip(xs, ys):
64 print(a, b)">COPY</button></div><p>Loop over two iterables</p></article><article class="card" data-search="conditionals &amp; loops while condition:
65 ... while loop"><div class="cmdrow"><pre><code>while condition:
66 ...</code></pre><button class="copy" data-copy="while condition:
67 ...">COPY</button></div><p>While loop</p></article><article class="card" data-search="conditionals &amp; loops break exit a loop"><div class="cmdrow"><pre><code>break</code></pre><button class="copy" data-copy="break">COPY</button></div><p>Exit a loop</p></article><article class="card" data-search="conditionals &amp; loops continue skip to next iteration"><div class="cmdrow"><pre><code>continue</code></pre><button class="copy" data-copy="continue">COPY</button></div><p>Skip to next iteration</p></article><article class="card" data-search="conditionals &amp; loops range(10) create a range"><div class="cmdrow"><pre><code>range(10)</code></pre><button class="copy" data-copy="range(10)">COPY</button></div><p>Create a range</p></article></div></div></section><section class="section" id="comprehensions"><button class="sectionhead"><span>Comprehensions</span><small>7 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="comprehensions [x * 2 for x in items] list comprehension"><div class="cmdrow"><pre><code>[x * 2 for x in items]</code></pre><button class="copy" data-copy="[x * 2 for x in items]">COPY</button></div><p>List comprehension</p></article><article class="card" data-search="comprehensions [x for x in items if x &gt; 0] filtered list comprehension"><div class="cmdrow"><pre><code>[x for x in items if x &gt; 0]</code></pre><button class="copy" data-copy="[x for x in items if x &gt; 0]">COPY</button></div><p>Filtered list comprehension</p></article><article class="card" data-search="comprehensions {x * 2 for x in items} set comprehension"><div class="cmdrow"><pre><code>{x * 2 for x in items}</code></pre><button class="copy" data-copy="{x * 2 for x in items}">COPY</button></div><p>Set comprehension</p></article><article class="card" data-search="comprehensions {k: v * 2 for k, v in data.items()} dictionary comprehension"><div class="cmdrow"><pre><code>{k: v * 2 for k, v in data.items()}</code></pre><button class="copy" data-copy="{k: v * 2 for k, v in data.items()}">COPY</button></div><p>Dictionary comprehension</p></article><article class="card" data-search="comprehensions (x * 2 for x in items) generator expression"><div class="cmdrow"><pre><code>(x * 2 for x in items)</code></pre><button class="copy" data-copy="(x * 2 for x in items)">COPY</button></div><p>Generator expression</p></article><article class="card" data-search="comprehensions [word.strip().lower() for word in lines if word.strip()] clean and filter text"><div class="cmdrow"><pre><code>[word.strip().lower() for word in lines if word.strip()]</code></pre><button class="copy" data-copy="[word.strip().lower() for word in lines if word.strip()]">COPY</button></div><p>Clean and filter text</p></article><article class="card" data-search="comprehensions [x for row in matrix for x in row] flatten one list level"><div class="cmdrow"><pre><code>[x for row in matrix for x in row]</code></pre><button class="copy" data-copy="[x for row in matrix for x in row]">COPY</button></div><p>Flatten one list level</p></article></div></div></section><section class="section" id="functions"><button class="sectionhead"><span>Functions</span><small>15 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="functions def greet(name):
68 return f&#x27;hello {name}&#x27; define a function"><div class="cmdrow"><pre><code>def greet(name):
69 return f&#x27;Hello {name}&#x27;</code></pre><button class="copy" data-copy="def greet(name):
70 return f&#x27;Hello {name}&#x27;">COPY</button></div><p>Define a function</p></article><article class="card" data-search="functions def add(a, b=0):
71 return a + b default argument"><div class="cmdrow"><pre><code>def add(a, b=0):
72 return a + b</code></pre><button class="copy" data-copy="def add(a, b=0):
73 return a + b">COPY</button></div><p>Default argument</p></article><article class="card" data-search="functions def func(*args):
74 print(args) variable positional arguments"><div class="cmdrow"><pre><code>def func(*args):
75 print(args)</code></pre><button class="copy" data-copy="def func(*args):
76 print(args)">COPY</button></div><p>Variable positional arguments</p></article><article class="card" data-search="functions def func(**kwargs):
77 print(kwargs) variable keyword arguments"><div class="cmdrow"><pre><code>def func(**kwargs):
78 print(kwargs)</code></pre><button class="copy" data-copy="def func(**kwargs):
79 print(kwargs)">COPY</button></div><p>Variable keyword arguments</p></article><article class="card" data-search="functions def func(a, /, b, *, c):
80 ... positional-only and keyword-only parameters"><div class="cmdrow"><pre><code>def func(a, /, b, *, c):
81 ...</code></pre><button class="copy" data-copy="def func(a, /, b, *, c):
82 ...">COPY</button></div><p>Positional-only and keyword-only parameters</p></article><article class="card" data-search="functions func(a=1, b=2) call with keyword arguments"><div class="cmdrow"><pre><code>func(a=1, b=2)</code></pre><button class="copy" data-copy="func(a=1, b=2)">COPY</button></div><p>Call with keyword arguments</p></article><article class="card" data-search="functions values = [1, 2]
83func(*values) unpack positional arguments"><div class="cmdrow"><pre><code>values = [1, 2]
84func(*values)</code></pre><button class="copy" data-copy="values = [1, 2]
85func(*values)">COPY</button></div><p>Unpack positional arguments</p></article><article class="card" data-search="functions options = {&#x27;a&#x27;: 1}
86func(**options) unpack keyword arguments"><div class="cmdrow"><pre><code>options = {&#x27;a&#x27;: 1}
87func(**options)</code></pre><button class="copy" data-copy="options = {&#x27;a&#x27;: 1}
88func(**options)">COPY</button></div><p>Unpack keyword arguments</p></article><article class="card" data-search="functions lambda x: x * 2 anonymous function"><div class="cmdrow"><pre><code>lambda x: x * 2</code></pre><button class="copy" data-copy="lambda x: x * 2">COPY</button></div><p>Anonymous function</p></article><article class="card" data-search="functions map(str.upper, words) map lazily"><div class="cmdrow"><pre><code>map(str.upper, words)</code></pre><button class="copy" data-copy="map(str.upper, words)">COPY</button></div><p>Map lazily</p></article><article class="card" data-search="functions filter(str.isalpha, values) filter lazily"><div class="cmdrow"><pre><code>filter(str.isalpha, values)</code></pre><button class="copy" data-copy="filter(str.isalpha, values)">COPY</button></div><p>Filter lazily</p></article><article class="card" data-search="functions return value return a value"><div class="cmdrow"><pre><code>return value</code></pre><button class="copy" data-copy="return value">COPY</button></div><p>Return a value</p></article><article class="card" data-search="functions yield value yield from a generator"><div class="cmdrow"><pre><code>yield value</code></pre><button class="copy" data-copy="yield value">COPY</button></div><p>Yield from a generator</p></article><article class="card" data-search="functions global name use a module-level name"><div class="cmdrow"><pre><code>global name</code></pre><button class="copy" data-copy="global name">COPY</button></div><p>Use a module-level name</p></article><article class="card" data-search="functions nonlocal name use an enclosing-scope name"><div class="cmdrow"><pre><code>nonlocal name</code></pre><button class="copy" data-copy="nonlocal name">COPY</button></div><p>Use an enclosing-scope name</p></article></div></div></section><section class="section" id="oop---classes"><button class="sectionhead"><span>Oop &amp; Classes</span><small>14 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="oop &amp; classes class user:
89 pass define a class"><div class="cmdrow"><pre><code>class User:
90 pass</code></pre><button class="copy" data-copy="class User:
91 pass">COPY</button></div><p>Define a class</p></article><article class="card" data-search="oop &amp; classes class user:
92 def __init__(self, name):
93 self.name = name define an initializer"><div class="cmdrow"><pre><code>class User:
94 def __init__(self, name):
95 self.name = name</code></pre><button class="copy" data-copy="class User:
96 def __init__(self, name):
97 self.name = name">COPY</button></div><p>Define an initializer</p></article><article class="card" data-search="oop &amp; classes u = user(&#x27;ada&#x27;) create an instance"><div class="cmdrow"><pre><code>u = User(&#x27;Ada&#x27;)</code></pre><button class="copy" data-copy="u = User(&#x27;Ada&#x27;)">COPY</button></div><p>Create an instance</p></article><article class="card" data-search="oop &amp; classes u.name access an attribute"><div class="cmdrow"><pre><code>u.name</code></pre><button class="copy" data-copy="u.name">COPY</button></div><p>Access an attribute</p></article><article class="card" data-search="oop &amp; classes class user:
98 def greet(self):
99 return self.name define an instance method"><div class="cmdrow"><pre><code>class User:
100 def greet(self):
101 return self.name</code></pre><button class="copy" data-copy="class User:
102 def greet(self):
103 return self.name">COPY</button></div><p>Define an instance method</p></article><article class="card" data-search="oop &amp; classes @classmethod
104def from_text(cls, text):
105 return cls(text) define a class method"><div class="cmdrow"><pre><code>@classmethod
106def from_text(cls, text):
107 return cls(text)</code></pre><button class="copy" data-copy="@classmethod
108def from_text(cls, text):
109 return cls(text)">COPY</button></div><p>Define a class method</p></article><article class="card" data-search="oop &amp; classes @staticmethod
110def validate(value):
111 return bool(value) define a static method"><div class="cmdrow"><pre><code>@staticmethod
112def validate(value):
113 return bool(value)</code></pre><button class="copy" data-copy="@staticmethod
114def validate(value):
115 return bool(value)">COPY</button></div><p>Define a static method</p></article><article class="card" data-search="oop &amp; classes class admin(user):
116 pass subclass another class"><div class="cmdrow"><pre><code>class Admin(User):
117 pass</code></pre><button class="copy" data-copy="class Admin(User):
118 pass">COPY</button></div><p>Subclass another class</p></article><article class="card" data-search="oop &amp; classes super().__init__(name) call parent initializer"><div class="cmdrow"><pre><code>super().__init__(name)</code></pre><button class="copy" data-copy="super().__init__(name)">COPY</button></div><p>Call parent initializer</p></article><article class="card" data-search="oop &amp; classes isinstance(obj, user) check instance type"><div class="cmdrow"><pre><code>isinstance(obj, User)</code></pre><button class="copy" data-copy="isinstance(obj, User)">COPY</button></div><p>Check instance type</p></article><article class="card" data-search="oop &amp; classes issubclass(admin, user) check inheritance"><div class="cmdrow"><pre><code>issubclass(Admin, User)</code></pre><button class="copy" data-copy="issubclass(Admin, User)">COPY</button></div><p>Check inheritance</p></article><article class="card" data-search="oop &amp; classes @property
119def full_name(self):
120 return self.name define a property"><div class="cmdrow"><pre><code>@property
121def full_name(self):
122 return self.name</code></pre><button class="copy" data-copy="@property
123def full_name(self):
124 return self.name">COPY</button></div><p>Define a property</p></article><article class="card" data-search="oop &amp; classes def __repr__(self):
125 return f&#x27;user({self.name!r})&#x27; customize repr"><div class="cmdrow"><pre><code>def __repr__(self):
126 return f&#x27;User({self.name!r})&#x27;</code></pre><button class="copy" data-copy="def __repr__(self):
127 return f&#x27;User({self.name!r})&#x27;">COPY</button></div><p>Customize repr</p></article><article class="card" data-search="oop &amp; classes def __str__(self):
128 return self.name customize str"><div class="cmdrow"><pre><code>def __str__(self):
129 return self.name</code></pre><button class="copy" data-copy="def __str__(self):
130 return self.name">COPY</button></div><p>Customize str</p></article></div></div></section><section class="section" id="exceptions"><button class="sectionhead"><span>Exceptions</span><small>9 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="exceptions try:
131 risky()
132except valueerror:
133 handle() catch a specific exception"><div class="cmdrow"><pre><code>try:
134 risky()
135except ValueError:
136 handle()</code></pre><button class="copy" data-copy="try:
137 risky()
138except ValueError:
139 handle()">COPY</button></div><p>Catch a specific exception</p></article><article class="card" data-search="exceptions try:
140 ...
141except (typeerror, valueerror) as e:
142 print(e) catch multiple exception types"><div class="cmdrow"><pre><code>try:
143 ...
144except (TypeError, ValueError) as e:
145 print(e)</code></pre><button class="copy" data-copy="try:
146 ...
147except (TypeError, ValueError) as e:
148 print(e)">COPY</button></div><p>Catch multiple exception types</p></article><article class="card" data-search="exceptions try:
149 ...
150except exception as e:
151 print(e) catch most normal exceptions"><div class="cmdrow"><pre><code>try:
152 ...
153except Exception as e:
154 print(e)</code></pre><button class="copy" data-copy="try:
155 ...
156except Exception as e:
157 print(e)">COPY</button></div><p>Catch most normal exceptions</p></article><article class="card" data-search="exceptions try:
158 ...
159else:
160 success() run else when no exception occurs"><div class="cmdrow"><pre><code>try:
161 ...
162else:
163 success()</code></pre><button class="copy" data-copy="try:
164 ...
165else:
166 success()">COPY</button></div><p>Run else when no exception occurs</p></article><article class="card" data-search="exceptions try:
167 ...
168finally:
169 cleanup() always run cleanup"><div class="cmdrow"><pre><code>try:
170 ...
171finally:
172 cleanup()</code></pre><button class="copy" data-copy="try:
173 ...
174finally:
175 cleanup()">COPY</button></div><p>Always run cleanup</p></article><article class="card" data-search="exceptions raise valueerror(&#x27;bad value&#x27;) raise an exception"><div class="cmdrow"><pre><code>raise ValueError(&#x27;bad value&#x27;)</code></pre><button class="copy" data-copy="raise ValueError(&#x27;bad value&#x27;)">COPY</button></div><p>Raise an exception</p></article><article class="card" data-search="exceptions raise re-raise current exception"><div class="cmdrow"><pre><code>raise</code></pre><button class="copy" data-copy="raise">COPY</button></div><p>Re-raise current exception</p></article><article class="card" data-search="exceptions assert x &gt; 0 development-time assertion"><div class="cmdrow"><pre><code>assert x &gt; 0</code></pre><button class="copy" data-copy="assert x &gt; 0">COPY</button></div><p>Development-time assertion</p></article><article class="card" data-search="exceptions class myerror(exception):
176 pass create a custom exception"><div class="cmdrow"><pre><code>class MyError(Exception):
177 pass</code></pre><button class="copy" data-copy="class MyError(Exception):
178 pass">COPY</button></div><p>Create a custom exception</p></article></div></div></section><section class="section" id="files---pathlib"><button class="sectionhead"><span>Files &amp; Pathlib</span><small>22 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="files &amp; pathlib from pathlib import path import path"><div class="cmdrow"><pre><code>from pathlib import Path</code></pre><button class="copy" data-copy="from pathlib import Path">COPY</button></div><p>Import Path</p></article><article class="card" data-search="files &amp; pathlib p = path(&#x27;file.txt&#x27;) create a path object"><div class="cmdrow"><pre><code>p = Path(&#x27;file.txt&#x27;)</code></pre><button class="copy" data-copy="p = Path(&#x27;file.txt&#x27;)">COPY</button></div><p>Create a Path object</p></article><article class="card" data-search="files &amp; pathlib p.exists() check whether path exists"><div class="cmdrow"><pre><code>p.exists()</code></pre><button class="copy" data-copy="p.exists()">COPY</button></div><p>Check whether path exists</p></article><article class="card" data-search="files &amp; pathlib p.is_file() check whether path is a file"><div class="cmdrow"><pre><code>p.is_file()</code></pre><button class="copy" data-copy="p.is_file()">COPY</button></div><p>Check whether path is a file</p></article><article class="card" data-search="files &amp; pathlib p.is_dir() check whether path is a directory"><div class="cmdrow"><pre><code>p.is_dir()</code></pre><button class="copy" data-copy="p.is_dir()">COPY</button></div><p>Check whether path is a directory</p></article><article class="card" data-search="files &amp; pathlib p.name get file name"><div class="cmdrow"><pre><code>p.name</code></pre><button class="copy" data-copy="p.name">COPY</button></div><p>Get file name</p></article><article class="card" data-search="files &amp; pathlib p.stem get filename without suffix"><div class="cmdrow"><pre><code>p.stem</code></pre><button class="copy" data-copy="p.stem">COPY</button></div><p>Get filename without suffix</p></article><article class="card" data-search="files &amp; pathlib p.suffix get extension"><div class="cmdrow"><pre><code>p.suffix</code></pre><button class="copy" data-copy="p.suffix">COPY</button></div><p>Get extension</p></article><article class="card" data-search="files &amp; pathlib p.parent get parent directory"><div class="cmdrow"><pre><code>p.parent</code></pre><button class="copy" data-copy="p.parent">COPY</button></div><p>Get parent directory</p></article><article class="card" data-search="files &amp; pathlib p.resolve() resolve absolute path"><div class="cmdrow"><pre><code>p.resolve()</code></pre><button class="copy" data-copy="p.resolve()">COPY</button></div><p>Resolve absolute path</p></article><article class="card" data-search="files &amp; pathlib p.read_text() read text"><div class="cmdrow"><pre><code>p.read_text()</code></pre><button class="copy" data-copy="p.read_text()">COPY</button></div><p>Read text</p></article><article class="card" data-search="files &amp; pathlib p.write_text(&#x27;hello&#x27;) write text"><div class="cmdrow"><pre><code>p.write_text(&#x27;hello&#x27;)</code></pre><button class="copy" data-copy="p.write_text(&#x27;hello&#x27;)">COPY</button></div><p>Write text</p></article><article class="card" data-search="files &amp; pathlib p.read_bytes() read bytes"><div class="cmdrow"><pre><code>p.read_bytes()</code></pre><button class="copy" data-copy="p.read_bytes()">COPY</button></div><p>Read bytes</p></article><article class="card" data-search="files &amp; pathlib p.write_bytes(data) write bytes"><div class="cmdrow"><pre><code>p.write_bytes(data)</code></pre><button class="copy" data-copy="p.write_bytes(data)">COPY</button></div><p>Write bytes</p></article><article class="card" data-search="files &amp; pathlib path(&#x27;newdir&#x27;).mkdir(exist_ok=true) create directory"><div class="cmdrow"><pre><code>Path(&#x27;newdir&#x27;).mkdir(exist_ok=True)</code></pre><button class="copy" data-copy="Path(&#x27;newdir&#x27;).mkdir(exist_ok=True)">COPY</button></div><p>Create directory</p></article><article class="card" data-search="files &amp; pathlib path(&#x27;a/b&#x27;).mkdir(parents=true, exist_ok=true) create nested directories"><div class="cmdrow"><pre><code>Path(&#x27;a/b&#x27;).mkdir(parents=True, exist_ok=True)</code></pre><button class="copy" data-copy="Path(&#x27;a/b&#x27;).mkdir(parents=True, exist_ok=True)">COPY</button></div><p>Create nested directories</p></article><article class="card" data-search="files &amp; pathlib list(path(&#x27;.&#x27;).iterdir()) list directory contents"><div class="cmdrow"><pre><code>list(Path(&#x27;.&#x27;).iterdir())</code></pre><button class="copy" data-copy="list(Path(&#x27;.&#x27;).iterdir())">COPY</button></div><p>List directory contents</p></article><article class="card" data-search="files &amp; pathlib list(path(&#x27;.&#x27;).glob(&#x27;*.py&#x27;)) glob files"><div class="cmdrow"><pre><code>list(Path(&#x27;.&#x27;).glob(&#x27;*.py&#x27;))</code></pre><button class="copy" data-copy="list(Path(&#x27;.&#x27;).glob(&#x27;*.py&#x27;))">COPY</button></div><p>Glob files</p></article><article class="card" data-search="files &amp; pathlib list(path(&#x27;.&#x27;).rglob(&#x27;*.py&#x27;)) recursive glob"><div class="cmdrow"><pre><code>list(Path(&#x27;.&#x27;).rglob(&#x27;*.py&#x27;))</code></pre><button class="copy" data-copy="list(Path(&#x27;.&#x27;).rglob(&#x27;*.py&#x27;))">COPY</button></div><p>Recursive glob</p></article><article class="card" data-search="files &amp; pathlib with open(&#x27;file.txt&#x27;, &#x27;r&#x27;, encoding=&#x27;utf-8&#x27;) as f:
179 text = f.read() read text with open"><div class="cmdrow"><pre><code>with open(&#x27;file.txt&#x27;, &#x27;r&#x27;, encoding=&#x27;utf-8&#x27;) as f:
180 text = f.read()</code></pre><button class="copy" data-copy="with open(&#x27;file.txt&#x27;, &#x27;r&#x27;, encoding=&#x27;utf-8&#x27;) as f:
181 text = f.read()">COPY</button></div><p>Read text with open</p></article><article class="card" data-search="files &amp; pathlib with open(&#x27;file.txt&#x27;, &#x27;w&#x27;, encoding=&#x27;utf-8&#x27;) as f:
182 f.write(&#x27;hello&#x27;) write text with open"><div class="cmdrow"><pre><code>with open(&#x27;file.txt&#x27;, &#x27;w&#x27;, encoding=&#x27;utf-8&#x27;) as f:
183 f.write(&#x27;hello&#x27;)</code></pre><button class="copy" data-copy="with open(&#x27;file.txt&#x27;, &#x27;w&#x27;, encoding=&#x27;utf-8&#x27;) as f:
184 f.write(&#x27;hello&#x27;)">COPY</button></div><p>Write text with open</p></article><article class="card" data-search="files &amp; pathlib with open(&#x27;file.txt&#x27;, &#x27;a&#x27;, encoding=&#x27;utf-8&#x27;) as f:
185 f.write(&#x27;more&#x27;) append text"><div class="cmdrow"><pre><code>with open(&#x27;file.txt&#x27;, &#x27;a&#x27;, encoding=&#x27;utf-8&#x27;) as f:
186 f.write(&#x27;more&#x27;)</code></pre><button class="copy" data-copy="with open(&#x27;file.txt&#x27;, &#x27;a&#x27;, encoding=&#x27;utf-8&#x27;) as f:
187 f.write(&#x27;more&#x27;)">COPY</button></div><p>Append text</p></article></div></div></section><section class="section" id="json---csv"><button class="sectionhead"><span>Json &amp; Csv</span><small>11 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="json &amp; csv import json import json tools"><div class="cmdrow"><pre><code>import json</code></pre><button class="copy" data-copy="import json">COPY</button></div><p>Import JSON tools</p></article><article class="card" data-search="json &amp; csv json.dumps(data) serialize to json string"><div class="cmdrow"><pre><code>json.dumps(data)</code></pre><button class="copy" data-copy="json.dumps(data)">COPY</button></div><p>Serialize to JSON string</p></article><article class="card" data-search="json &amp; csv json.dumps(data, indent=2) pretty json"><div class="cmdrow"><pre><code>json.dumps(data, indent=2)</code></pre><button class="copy" data-copy="json.dumps(data, indent=2)">COPY</button></div><p>Pretty JSON</p></article><article class="card" data-search="json &amp; csv json.loads(text) parse json string"><div class="cmdrow"><pre><code>json.loads(text)</code></pre><button class="copy" data-copy="json.loads(text)">COPY</button></div><p>Parse JSON string</p></article><article class="card" data-search="json &amp; csv json.dump(data, file_obj) write json to file"><div class="cmdrow"><pre><code>json.dump(data, file_obj)</code></pre><button class="copy" data-copy="json.dump(data, file_obj)">COPY</button></div><p>Write JSON to file</p></article><article class="card" data-search="json &amp; csv json.load(file_obj) read json from file"><div class="cmdrow"><pre><code>json.load(file_obj)</code></pre><button class="copy" data-copy="json.load(file_obj)">COPY</button></div><p>Read JSON from file</p></article><article class="card" data-search="json &amp; csv import csv import csv tools"><div class="cmdrow"><pre><code>import csv</code></pre><button class="copy" data-copy="import csv">COPY</button></div><p>Import CSV tools</p></article><article class="card" data-search="json &amp; csv csv.reader(file_obj) read csv rows"><div class="cmdrow"><pre><code>csv.reader(file_obj)</code></pre><button class="copy" data-copy="csv.reader(file_obj)">COPY</button></div><p>Read CSV rows</p></article><article class="card" data-search="json &amp; csv csv.writer(file_obj) write csv rows"><div class="cmdrow"><pre><code>csv.writer(file_obj)</code></pre><button class="copy" data-copy="csv.writer(file_obj)">COPY</button></div><p>Write CSV rows</p></article><article class="card" data-search="json &amp; csv csv.dictreader(file_obj) read csv as dictionaries"><div class="cmdrow"><pre><code>csv.DictReader(file_obj)</code></pre><button class="copy" data-copy="csv.DictReader(file_obj)">COPY</button></div><p>Read CSV as dictionaries</p></article><article class="card" data-search="json &amp; csv csv.dictwriter(file_obj, fieldnames=fields) write dictionary rows"><div class="cmdrow"><pre><code>csv.DictWriter(file_obj, fieldnames=fields)</code></pre><button class="copy" data-copy="csv.DictWriter(file_obj, fieldnames=fields)">COPY</button></div><p>Write dictionary rows</p></article></div></div></section><section class="section" id="datetime---time"><button class="sectionhead"><span>Datetime &amp; Time</span><small>12 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="datetime &amp; time from datetime import datetime, date, timedelta import date/time classes"><div class="cmdrow"><pre><code>from datetime import datetime, date, timedelta</code></pre><button class="copy" data-copy="from datetime import datetime, date, timedelta">COPY</button></div><p>Import date/time classes</p></article><article class="card" data-search="datetime &amp; time datetime.now() current local date and time"><div class="cmdrow"><pre><code>datetime.now()</code></pre><button class="copy" data-copy="datetime.now()">COPY</button></div><p>Current local date and time</p></article><article class="card" data-search="datetime &amp; time date.today() today&#x27;s date"><div class="cmdrow"><pre><code>date.today()</code></pre><button class="copy" data-copy="date.today()">COPY</button></div><p>Today&#x27;s date</p></article><article class="card" data-search="datetime &amp; time datetime.now().isoformat() iso 8601 string"><div class="cmdrow"><pre><code>datetime.now().isoformat()</code></pre><button class="copy" data-copy="datetime.now().isoformat()">COPY</button></div><p>ISO 8601 string</p></article><article class="card" data-search="datetime &amp; time datetime.fromisoformat(&#x27;2026-09-18t15:30:00&#x27;) parse iso datetime"><div class="cmdrow"><pre><code>datetime.fromisoformat(&#x27;2026-09-18T15:30:00&#x27;)</code></pre><button class="copy" data-copy="datetime.fromisoformat(&#x27;2026-09-18T15:30:00&#x27;)">COPY</button></div><p>Parse ISO datetime</p></article><article class="card" data-search="datetime &amp; time datetime.strptime(&#x27;09/18/2026&#x27;, &#x27;%m/%d/%y&#x27;) parse formatted date"><div class="cmdrow"><pre><code>datetime.strptime(&#x27;09/18/2026&#x27;, &#x27;%m/%d/%Y&#x27;)</code></pre><button class="copy" data-copy="datetime.strptime(&#x27;09/18/2026&#x27;, &#x27;%m/%d/%Y&#x27;)">COPY</button></div><p>Parse formatted date</p></article><article class="card" data-search="datetime &amp; time datetime.now().strftime(&#x27;%y-%m-%d&#x27;) format date/time"><div class="cmdrow"><pre><code>datetime.now().strftime(&#x27;%Y-%m-%d&#x27;)</code></pre><button class="copy" data-copy="datetime.now().strftime(&#x27;%Y-%m-%d&#x27;)">COPY</button></div><p>Format date/time</p></article><article class="card" data-search="datetime &amp; time datetime.now() + timedelta(days=7) add seven days"><div class="cmdrow"><pre><code>datetime.now() + timedelta(days=7)</code></pre><button class="copy" data-copy="datetime.now() + timedelta(days=7)">COPY</button></div><p>Add seven days</p></article><article class="card" data-search="datetime &amp; time (end - start).total_seconds() elapsed seconds"><div class="cmdrow"><pre><code>(end - start).total_seconds()</code></pre><button class="copy" data-copy="(end - start).total_seconds()">COPY</button></div><p>Elapsed seconds</p></article><article class="card" data-search="datetime &amp; time import time
188time.sleep(1) sleep one second"><div class="cmdrow"><pre><code>import time
189time.sleep(1)</code></pre><button class="copy" data-copy="import time
190time.sleep(1)">COPY</button></div><p>Sleep one second</p></article><article class="card" data-search="datetime &amp; time time.time() unix timestamp"><div class="cmdrow"><pre><code>time.time()</code></pre><button class="copy" data-copy="time.time()">COPY</button></div><p>Unix timestamp</p></article><article class="card" data-search="datetime &amp; time time.perf_counter() high-resolution timer"><div class="cmdrow"><pre><code>time.perf_counter()</code></pre><button class="copy" data-copy="time.perf_counter()">COPY</button></div><p>High-resolution timer</p></article></div></div></section><section class="section" id="regex"><button class="sectionhead"><span>Regex</span><small>10 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="regex import re import regular expressions"><div class="cmdrow"><pre><code>import re</code></pre><button class="copy" data-copy="import re">COPY</button></div><p>Import regular expressions</p></article><article class="card" data-search="regex re.search(r&#x27;\\d+&#x27;, text) find first digit sequence"><div class="cmdrow"><pre><code>re.search(r&#x27;\\d+&#x27;, text)</code></pre><button class="copy" data-copy="re.search(r&#x27;\\d+&#x27;, text)">COPY</button></div><p>Find first digit sequence</p></article><article class="card" data-search="regex re.match(r&#x27;\\w+&#x27;, text) match from string start"><div class="cmdrow"><pre><code>re.match(r&#x27;\\w+&#x27;, text)</code></pre><button class="copy" data-copy="re.match(r&#x27;\\w+&#x27;, text)">COPY</button></div><p>Match from string start</p></article><article class="card" data-search="regex re.fullmatch(r&#x27;\\d{4}&#x27;, text) require a full match"><div class="cmdrow"><pre><code>re.fullmatch(r&#x27;\\d{4}&#x27;, text)</code></pre><button class="copy" data-copy="re.fullmatch(r&#x27;\\d{4}&#x27;, text)">COPY</button></div><p>Require a full match</p></article><article class="card" data-search="regex re.findall(r&#x27;\\b\\w+\\b&#x27;, text) return all matches"><div class="cmdrow"><pre><code>re.findall(r&#x27;\\b\\w+\\b&#x27;, text)</code></pre><button class="copy" data-copy="re.findall(r&#x27;\\b\\w+\\b&#x27;, text)">COPY</button></div><p>Return all matches</p></article><article class="card" data-search="regex re.sub(r&#x27;\\s+&#x27;, &#x27; &#x27;, text) replace repeated whitespace"><div class="cmdrow"><pre><code>re.sub(r&#x27;\\s+&#x27;, &#x27; &#x27;, text)</code></pre><button class="copy" data-copy="re.sub(r&#x27;\\s+&#x27;, &#x27; &#x27;, text)">COPY</button></div><p>Replace repeated whitespace</p></article><article class="card" data-search="regex re.split(r&#x27;[,;]&#x27;, text) split using regex"><div class="cmdrow"><pre><code>re.split(r&#x27;[,;]&#x27;, text)</code></pre><button class="copy" data-copy="re.split(r&#x27;[,;]&#x27;, text)">COPY</button></div><p>Split using regex</p></article><article class="card" data-search="regex pattern = re.compile(r&#x27;\\d+&#x27;) compile a reusable pattern"><div class="cmdrow"><pre><code>pattern = re.compile(r&#x27;\\d+&#x27;)</code></pre><button class="copy" data-copy="pattern = re.compile(r&#x27;\\d+&#x27;)">COPY</button></div><p>Compile a reusable pattern</p></article><article class="card" data-search="regex m.group(0) read full match"><div class="cmdrow"><pre><code>m.group(0)</code></pre><button class="copy" data-copy="m.group(0)">COPY</button></div><p>Read full match</p></article><article class="card" data-search="regex m.groups() read captured groups"><div class="cmdrow"><pre><code>m.groups()</code></pre><button class="copy" data-copy="m.groups()">COPY</button></div><p>Read captured groups</p></article></div></div></section><section class="section" id="math---random"><button class="sectionhead"><span>Math &amp; Random</span><small>15 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="math &amp; random import math import math module"><div class="cmdrow"><pre><code>import math</code></pre><button class="copy" data-copy="import math">COPY</button></div><p>Import math module</p></article><article class="card" data-search="math &amp; random math.sqrt(81) square root"><div class="cmdrow"><pre><code>math.sqrt(81)</code></pre><button class="copy" data-copy="math.sqrt(81)">COPY</button></div><p>Square root</p></article><article class="card" data-search="math &amp; random math.ceil(3.2) round upward"><div class="cmdrow"><pre><code>math.ceil(3.2)</code></pre><button class="copy" data-copy="math.ceil(3.2)">COPY</button></div><p>Round upward</p></article><article class="card" data-search="math &amp; random math.floor(3.8) round downward"><div class="cmdrow"><pre><code>math.floor(3.8)</code></pre><button class="copy" data-copy="math.floor(3.8)">COPY</button></div><p>Round downward</p></article><article class="card" data-search="math &amp; random math.pi pi constant"><div class="cmdrow"><pre><code>math.pi</code></pre><button class="copy" data-copy="math.pi">COPY</button></div><p>Pi constant</p></article><article class="card" data-search="math &amp; random math.isclose(a, b) compare floats approximately"><div class="cmdrow"><pre><code>math.isclose(a, b)</code></pre><button class="copy" data-copy="math.isclose(a, b)">COPY</button></div><p>Compare floats approximately</p></article><article class="card" data-search="math &amp; random import statistics import statistics module"><div class="cmdrow"><pre><code>import statistics</code></pre><button class="copy" data-copy="import statistics">COPY</button></div><p>Import statistics module</p></article><article class="card" data-search="math &amp; random statistics.mean(values) mean"><div class="cmdrow"><pre><code>statistics.mean(values)</code></pre><button class="copy" data-copy="statistics.mean(values)">COPY</button></div><p>Mean</p></article><article class="card" data-search="math &amp; random statistics.median(values) median"><div class="cmdrow"><pre><code>statistics.median(values)</code></pre><button class="copy" data-copy="statistics.median(values)">COPY</button></div><p>Median</p></article><article class="card" data-search="math &amp; random statistics.stdev(values) sample standard deviation"><div class="cmdrow"><pre><code>statistics.stdev(values)</code></pre><button class="copy" data-copy="statistics.stdev(values)">COPY</button></div><p>Sample standard deviation</p></article><article class="card" data-search="math &amp; random import random import pseudo-random tools"><div class="cmdrow"><pre><code>import random</code></pre><button class="copy" data-copy="import random">COPY</button></div><p>Import pseudo-random tools</p></article><article class="card" data-search="math &amp; random random.randint(1, 10) random integer"><div class="cmdrow"><pre><code>random.randint(1, 10)</code></pre><button class="copy" data-copy="random.randint(1, 10)">COPY</button></div><p>Random integer</p></article><article class="card" data-search="math &amp; random random.choice(items) choose one random item"><div class="cmdrow"><pre><code>random.choice(items)</code></pre><button class="copy" data-copy="random.choice(items)">COPY</button></div><p>Choose one random item</p></article><article class="card" data-search="math &amp; random random.sample(items, 3) choose unique random items"><div class="cmdrow"><pre><code>random.sample(items, 3)</code></pre><button class="copy" data-copy="random.sample(items, 3)">COPY</button></div><p>Choose unique random items</p></article><article class="card" data-search="math &amp; random random.shuffle(items) shuffle a list in place"><div class="cmdrow"><pre><code>random.shuffle(items)</code></pre><button class="copy" data-copy="random.shuffle(items)">COPY</button></div><p>Shuffle a list in place</p></article></div></div></section><section class="section" id="iterators---generators"><button class="sectionhead"><span>Iterators &amp; Generators</span><small>9 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="iterators &amp; generators iter(items) get an iterator"><div class="cmdrow"><pre><code>iter(items)</code></pre><button class="copy" data-copy="iter(items)">COPY</button></div><p>Get an iterator</p></article><article class="card" data-search="iterators &amp; generators next(iterator) get next item"><div class="cmdrow"><pre><code>next(iterator)</code></pre><button class="copy" data-copy="next(iterator)">COPY</button></div><p>Get next item</p></article><article class="card" data-search="iterators &amp; generators next(iterator, default) get next or default"><div class="cmdrow"><pre><code>next(iterator, default)</code></pre><button class="copy" data-copy="next(iterator, default)">COPY</button></div><p>Get next or default</p></article><article class="card" data-search="iterators &amp; generators def countdown(n):
191 while n:
192 yield n
193 n -= 1 create generator function"><div class="cmdrow"><pre><code>def countdown(n):
194 while n:
195 yield n
196 n -= 1</code></pre><button class="copy" data-copy="def countdown(n):
197 while n:
198 yield n
199 n -= 1">COPY</button></div><p>Create generator function</p></article><article class="card" data-search="iterators &amp; generators (x * x for x in range(10)) generator expression"><div class="cmdrow"><pre><code>(x * x for x in range(10))</code></pre><button class="copy" data-copy="(x * x for x in range(10))">COPY</button></div><p>Generator expression</p></article><article class="card" data-search="iterators &amp; generators yield from iterable yield from another iterable"><div class="cmdrow"><pre><code>yield from iterable</code></pre><button class="copy" data-copy="yield from iterable">COPY</button></div><p>Yield from another iterable</p></article><article class="card" data-search="iterators &amp; generators enumerate(items, start=1) enumerate starting at 1"><div class="cmdrow"><pre><code>enumerate(items, start=1)</code></pre><button class="copy" data-copy="enumerate(items, start=1)">COPY</button></div><p>Enumerate starting at 1</p></article><article class="card" data-search="iterators &amp; generators zip(a, b) pair iterables"><div class="cmdrow"><pre><code>zip(a, b)</code></pre><button class="copy" data-copy="zip(a, b)">COPY</button></div><p>Pair iterables</p></article><article class="card" data-search="iterators &amp; generators reversed(items) reverse iterator"><div class="cmdrow"><pre><code>reversed(items)</code></pre><button class="copy" data-copy="reversed(items)">COPY</button></div><p>Reverse iterator</p></article></div></div></section><section class="section" id="modules--venv---pip"><button class="sectionhead"><span>Modules, Venv &amp; Pip</span><small>17 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="modules, venv &amp; pip import os import a module"><div class="cmdrow"><pre><code>import os</code></pre><button class="copy" data-copy="import os">COPY</button></div><p>Import a module</p></article><article class="card" data-search="modules, venv &amp; pip import math as m import with alias"><div class="cmdrow"><pre><code>import math as m</code></pre><button class="copy" data-copy="import math as m">COPY</button></div><p>Import with alias</p></article><article class="card" data-search="modules, venv &amp; pip from pathlib import path import an object"><div class="cmdrow"><pre><code>from pathlib import Path</code></pre><button class="copy" data-copy="from pathlib import Path">COPY</button></div><p>Import an object</p></article><article class="card" data-search="modules, venv &amp; pip if __name__ == &#x27;__main__&#x27;:
200 main() run only when executed directly"><div class="cmdrow"><pre><code>if __name__ == &#x27;__main__&#x27;:
201 main()</code></pre><button class="copy" data-copy="if __name__ == &#x27;__main__&#x27;:
202 main()">COPY</button></div><p>Run only when executed directly</p></article><article class="card" data-search="modules, venv &amp; pip __name__ current module name"><div class="cmdrow"><pre><code>__name__</code></pre><button class="copy" data-copy="__name__">COPY</button></div><p>Current module name</p></article><article class="card" data-search="modules, venv &amp; pip __file__ current module file path"><div class="cmdrow"><pre><code>__file__</code></pre><button class="copy" data-copy="__file__">COPY</button></div><p>Current module file path</p></article><article class="card" data-search="modules, venv &amp; pip python -m venv .venv create a virtual environment"><div class="cmdrow"><pre><code>python -m venv .venv</code></pre><button class="copy" data-copy="python -m venv .venv">COPY</button></div><p>Create a virtual environment</p></article><article class="card" data-search="modules, venv &amp; pip source .venv/bin/activate activate venv on linux/macos"><div class="cmdrow"><pre><code>source .venv/bin/activate</code></pre><button class="copy" data-copy="source .venv/bin/activate">COPY</button></div><p>Activate venv on Linux/macOS</p></article><article class="card" data-search="modules, venv &amp; pip .venv\\scripts\\activate activate venv in windows command prompt"><div class="cmdrow"><pre><code>.venv\\Scripts\\activate</code></pre><button class="copy" data-copy=".venv\\Scripts\\activate">COPY</button></div><p>Activate venv in Windows Command Prompt</p></article><article class="card" data-search="modules, venv &amp; pip python -m pip install package install package"><div class="cmdrow"><pre><code>python -m pip install package</code></pre><button class="copy" data-copy="python -m pip install package">COPY</button></div><p>Install package</p></article><article class="card" data-search="modules, venv &amp; pip python -m pip install -u package upgrade package"><div class="cmdrow"><pre><code>python -m pip install -U package</code></pre><button class="copy" data-copy="python -m pip install -U package">COPY</button></div><p>Upgrade package</p></article><article class="card" data-search="modules, venv &amp; pip python -m pip uninstall package uninstall package"><div class="cmdrow"><pre><code>python -m pip uninstall package</code></pre><button class="copy" data-copy="python -m pip uninstall package">COPY</button></div><p>Uninstall package</p></article><article class="card" data-search="modules, venv &amp; pip python -m pip list list installed packages"><div class="cmdrow"><pre><code>python -m pip list</code></pre><button class="copy" data-copy="python -m pip list">COPY</button></div><p>List installed packages</p></article><article class="card" data-search="modules, venv &amp; pip python -m pip freeze print installed versions"><div class="cmdrow"><pre><code>python -m pip freeze</code></pre><button class="copy" data-copy="python -m pip freeze">COPY</button></div><p>Print installed versions</p></article><article class="card" data-search="modules, venv &amp; pip python -m pip freeze &gt; requirements.txt save requirements"><div class="cmdrow"><pre><code>python -m pip freeze &gt; requirements.txt</code></pre><button class="copy" data-copy="python -m pip freeze &gt; requirements.txt">COPY</button></div><p>Save requirements</p></article><article class="card" data-search="modules, venv &amp; pip python -m pip install -r requirements.txt install requirements"><div class="cmdrow"><pre><code>python -m pip install -r requirements.txt</code></pre><button class="copy" data-copy="python -m pip install -r requirements.txt">COPY</button></div><p>Install requirements</p></article><article class="card" data-search="modules, venv &amp; pip python -m pip show package show package metadata"><div class="cmdrow"><pre><code>python -m pip show package</code></pre><button class="copy" data-copy="python -m pip show package">COPY</button></div><p>Show package metadata</p></article></div></div></section><section class="section" id="typing---dataclasses"><button class="sectionhead"><span>Typing &amp; Dataclasses</span><small>11 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="typing &amp; dataclasses def add(a: int, b: int) -&gt; int:
203 return a + b function type hints"><div class="cmdrow"><pre><code>def add(a: int, b: int) -&gt; int:
204 return a + b</code></pre><button class="copy" data-copy="def add(a: int, b: int) -&gt; int:
205 return a + b">COPY</button></div><p>Function type hints</p></article><article class="card" data-search="typing &amp; dataclasses name: str = &#x27;ada&#x27; variable annotation"><div class="cmdrow"><pre><code>name: str = &#x27;Ada&#x27;</code></pre><button class="copy" data-copy="name: str = &#x27;Ada&#x27;">COPY</button></div><p>Variable annotation</p></article><article class="card" data-search="typing &amp; dataclasses items: list[str] = [] list type hint"><div class="cmdrow"><pre><code>items: list[str] = []</code></pre><button class="copy" data-copy="items: list[str] = []">COPY</button></div><p>List type hint</p></article><article class="card" data-search="typing &amp; dataclasses mapping: dict[str, int] = {} dictionary type hint"><div class="cmdrow"><pre><code>mapping: dict[str, int] = {}</code></pre><button class="copy" data-copy="mapping: dict[str, int] = {}">COPY</button></div><p>Dictionary type hint</p></article><article class="card" data-search="typing &amp; dataclasses value: int none = none|optional value"><div class="cmdrow"><pre><code>value: int </code></pre><button class="copy" data-copy="value: int ">COPY</button></div><p> None = None|Optional value</p></article><article class="card" data-search="typing &amp; dataclasses from typing import any import any"><div class="cmdrow"><pre><code>from typing import Any</code></pre><button class="copy" data-copy="from typing import Any">COPY</button></div><p>Import Any</p></article><article class="card" data-search="typing &amp; dataclasses def func(value: any) -&gt; none:
206 ... accept any type"><div class="cmdrow"><pre><code>def func(value: Any) -&gt; None:
207 ...</code></pre><button class="copy" data-copy="def func(value: Any) -&gt; None:
208 ...">COPY</button></div><p>Accept any type</p></article><article class="card" data-search="typing &amp; dataclasses from dataclasses import dataclass import dataclass"><div class="cmdrow"><pre><code>from dataclasses import dataclass</code></pre><button class="copy" data-copy="from dataclasses import dataclass">COPY</button></div><p>Import dataclass</p></article><article class="card" data-search="typing &amp; dataclasses @dataclass
209class user:
210 name: str
211 age: int = 0 define a dataclass"><div class="cmdrow"><pre><code>@dataclass
212class User:
213 name: str
214 age: int = 0</code></pre><button class="copy" data-copy="@dataclass
215class User:
216 name: str
217 age: int = 0">COPY</button></div><p>Define a dataclass</p></article><article class="card" data-search="typing &amp; dataclasses from typing import typeddict import typeddict"><div class="cmdrow"><pre><code>from typing import TypedDict</code></pre><button class="copy" data-copy="from typing import TypedDict">COPY</button></div><p>Import TypedDict</p></article><article class="card" data-search="typing &amp; dataclasses class userdata(typeddict):
218 name: str
219 age: int type a dictionary shape"><div class="cmdrow"><pre><code>class UserData(TypedDict):
220 name: str
221 age: int</code></pre><button class="copy" data-copy="class UserData(TypedDict):
222 name: str
223 age: int">COPY</button></div><p>Type a dictionary shape</p></article></div></div></section><section class="section" id="os--sys---subprocess"><button class="sectionhead"><span>Os, Sys &amp; Subprocess</span><small>18 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="os, sys &amp; subprocess import os import os helpers"><div class="cmdrow"><pre><code>import os</code></pre><button class="copy" data-copy="import os">COPY</button></div><p>Import OS helpers</p></article><article class="card" data-search="os, sys &amp; subprocess os.getcwd() get working directory"><div class="cmdrow"><pre><code>os.getcwd()</code></pre><button class="copy" data-copy="os.getcwd()">COPY</button></div><p>Get working directory</p></article><article class="card" data-search="os, sys &amp; subprocess os.chdir(&#x27;/tmp&#x27;) change working directory"><div class="cmdrow"><pre><code>os.chdir(&#x27;/tmp&#x27;)</code></pre><button class="copy" data-copy="os.chdir(&#x27;/tmp&#x27;)">COPY</button></div><p>Change working directory</p></article><article class="card" data-search="os, sys &amp; subprocess os.environ.get(&#x27;home&#x27;) read environment variable"><div class="cmdrow"><pre><code>os.environ.get(&#x27;HOME&#x27;)</code></pre><button class="copy" data-copy="os.environ.get(&#x27;HOME&#x27;)">COPY</button></div><p>Read environment variable</p></article><article class="card" data-search="os, sys &amp; subprocess os.environ[&#x27;mode&#x27;] = &#x27;dev&#x27; set process environment variable"><div class="cmdrow"><pre><code>os.environ[&#x27;MODE&#x27;] = &#x27;dev&#x27;</code></pre><button class="copy" data-copy="os.environ[&#x27;MODE&#x27;] = &#x27;dev&#x27;">COPY</button></div><p>Set process environment variable</p></article><article class="card" data-search="os, sys &amp; subprocess os.listdir(&#x27;.&#x27;) list directory contents"><div class="cmdrow"><pre><code>os.listdir(&#x27;.&#x27;)</code></pre><button class="copy" data-copy="os.listdir(&#x27;.&#x27;)">COPY</button></div><p>List directory contents</p></article><article class="card" data-search="os, sys &amp; subprocess os.stat(&#x27;file.txt&#x27;) get file metadata"><div class="cmdrow"><pre><code>os.stat(&#x27;file.txt&#x27;)</code></pre><button class="copy" data-copy="os.stat(&#x27;file.txt&#x27;)">COPY</button></div><p>Get file metadata</p></article><article class="card" data-search="os, sys &amp; subprocess import sys import interpreter helpers"><div class="cmdrow"><pre><code>import sys</code></pre><button class="copy" data-copy="import sys">COPY</button></div><p>Import interpreter helpers</p></article><article class="card" data-search="os, sys &amp; subprocess sys.argv command-line arguments"><div class="cmdrow"><pre><code>sys.argv</code></pre><button class="copy" data-copy="sys.argv">COPY</button></div><p>Command-line arguments</p></article><article class="card" data-search="os, sys &amp; subprocess sys.version python version string"><div class="cmdrow"><pre><code>sys.version</code></pre><button class="copy" data-copy="sys.version">COPY</button></div><p>Python version string</p></article><article class="card" data-search="os, sys &amp; subprocess sys.platform platform identifier"><div class="cmdrow"><pre><code>sys.platform</code></pre><button class="copy" data-copy="sys.platform">COPY</button></div><p>Platform identifier</p></article><article class="card" data-search="os, sys &amp; subprocess sys.exit(0) exit program"><div class="cmdrow"><pre><code>sys.exit(0)</code></pre><button class="copy" data-copy="sys.exit(0)">COPY</button></div><p>Exit program</p></article><article class="card" data-search="os, sys &amp; subprocess import subprocess import subprocess module"><div class="cmdrow"><pre><code>import subprocess</code></pre><button class="copy" data-copy="import subprocess">COPY</button></div><p>Import subprocess module</p></article><article class="card" data-search="os, sys &amp; subprocess subprocess.run([&#x27;ls&#x27;, &#x27;-lah&#x27;]) run an external command"><div class="cmdrow"><pre><code>subprocess.run([&#x27;ls&#x27;, &#x27;-lah&#x27;])</code></pre><button class="copy" data-copy="subprocess.run([&#x27;ls&#x27;, &#x27;-lah&#x27;])">COPY</button></div><p>Run an external command</p></article><article class="card" data-search="os, sys &amp; subprocess subprocess.run([&#x27;cmd&#x27;], check=true) raise if command fails"><div class="cmdrow"><pre><code>subprocess.run([&#x27;cmd&#x27;], check=True)</code></pre><button class="copy" data-copy="subprocess.run([&#x27;cmd&#x27;], check=True)">COPY</button></div><p>Raise if command fails</p></article><article class="card" data-search="os, sys &amp; subprocess subprocess.run([&#x27;cmd&#x27;], capture_output=true, text=true) capture command output"><div class="cmdrow"><pre><code>subprocess.run([&#x27;cmd&#x27;], capture_output=True, text=True)</code></pre><button class="copy" data-copy="subprocess.run([&#x27;cmd&#x27;], capture_output=True, text=True)">COPY</button></div><p>Capture command output</p></article><article class="card" data-search="os, sys &amp; subprocess result.stdout captured stdout"><div class="cmdrow"><pre><code>result.stdout</code></pre><button class="copy" data-copy="result.stdout">COPY</button></div><p>Captured stdout</p></article><article class="card" data-search="os, sys &amp; subprocess result.returncode exit status"><div class="cmdrow"><pre><code>result.returncode</code></pre><button class="copy" data-copy="result.returncode">COPY</button></div><p>Exit status</p></article></div></div></section><section class="section" id="collections---functools"><button class="sectionhead"><span>Collections &amp; Functools</span><small>13 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="collections &amp; functools from collections import counter import counter"><div class="cmdrow"><pre><code>from collections import Counter</code></pre><button class="copy" data-copy="from collections import Counter">COPY</button></div><p>Import Counter</p></article><article class="card" data-search="collections &amp; functools counter(words) count values"><div class="cmdrow"><pre><code>Counter(words)</code></pre><button class="copy" data-copy="Counter(words)">COPY</button></div><p>Count values</p></article><article class="card" data-search="collections &amp; functools counter(words).most_common(5) most common values"><div class="cmdrow"><pre><code>Counter(words).most_common(5)</code></pre><button class="copy" data-copy="Counter(words).most_common(5)">COPY</button></div><p>Most common values</p></article><article class="card" data-search="collections &amp; functools from collections import defaultdict import defaultdict"><div class="cmdrow"><pre><code>from collections import defaultdict</code></pre><button class="copy" data-copy="from collections import defaultdict">COPY</button></div><p>Import defaultdict</p></article><article class="card" data-search="collections &amp; functools defaultdict(list) dictionary with automatic list defaults"><div class="cmdrow"><pre><code>defaultdict(list)</code></pre><button class="copy" data-copy="defaultdict(list)">COPY</button></div><p>Dictionary with automatic list defaults</p></article><article class="card" data-search="collections &amp; functools from collections import deque import deque"><div class="cmdrow"><pre><code>from collections import deque</code></pre><button class="copy" data-copy="from collections import deque">COPY</button></div><p>Import deque</p></article><article class="card" data-search="collections &amp; functools deque(items) create double-ended queue"><div class="cmdrow"><pre><code>deque(items)</code></pre><button class="copy" data-copy="deque(items)">COPY</button></div><p>Create double-ended queue</p></article><article class="card" data-search="collections &amp; functools q.appendleft(value) append to left"><div class="cmdrow"><pre><code>q.appendleft(value)</code></pre><button class="copy" data-copy="q.appendleft(value)">COPY</button></div><p>Append to left</p></article><article class="card" data-search="collections &amp; functools q.popleft() pop from left"><div class="cmdrow"><pre><code>q.popleft()</code></pre><button class="copy" data-copy="q.popleft()">COPY</button></div><p>Pop from left</p></article><article class="card" data-search="collections &amp; functools from functools import lru_cache import memoization helper"><div class="cmdrow"><pre><code>from functools import lru_cache</code></pre><button class="copy" data-copy="from functools import lru_cache">COPY</button></div><p>Import memoization helper</p></article><article class="card" data-search="collections &amp; functools @lru_cache(maxsize=none) cache function results"><div class="cmdrow"><pre><code>@lru_cache(maxsize=None)</code></pre><button class="copy" data-copy="@lru_cache(maxsize=None)">COPY</button></div><p>Cache function results</p></article><article class="card" data-search="collections &amp; functools from functools import partial import partial"><div class="cmdrow"><pre><code>from functools import partial</code></pre><button class="copy" data-copy="from functools import partial">COPY</button></div><p>Import partial</p></article><article class="card" data-search="collections &amp; functools partial(func, fixed_arg) pre-fill function arguments"><div class="cmdrow"><pre><code>partial(func, fixed_arg)</code></pre><button class="copy" data-copy="partial(func, fixed_arg)">COPY</button></div><p>Pre-fill function arguments</p></article></div></div></section><section class="section" id="logging---cli"><button class="sectionhead"><span>Logging &amp; Cli</span><small>14 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="logging &amp; cli import logging import logging"><div class="cmdrow"><pre><code>import logging</code></pre><button class="copy" data-copy="import logging">COPY</button></div><p>Import logging</p></article><article class="card" data-search="logging &amp; cli logging.basicconfig(level=logging.info) configure basic logging"><div class="cmdrow"><pre><code>logging.basicConfig(level=logging.INFO)</code></pre><button class="copy" data-copy="logging.basicConfig(level=logging.INFO)">COPY</button></div><p>Configure basic logging</p></article><article class="card" data-search="logging &amp; cli logging.info(&#x27;started&#x27;) info message"><div class="cmdrow"><pre><code>logging.info(&#x27;Started&#x27;)</code></pre><button class="copy" data-copy="logging.info(&#x27;Started&#x27;)">COPY</button></div><p>Info message</p></article><article class="card" data-search="logging &amp; cli logging.warning(&#x27;something odd happened&#x27;) warning message"><div class="cmdrow"><pre><code>logging.warning(&#x27;Something odd happened&#x27;)</code></pre><button class="copy" data-copy="logging.warning(&#x27;Something odd happened&#x27;)">COPY</button></div><p>Warning message</p></article><article class="card" data-search="logging &amp; cli logging.error(&#x27;failed&#x27;) error message"><div class="cmdrow"><pre><code>logging.error(&#x27;Failed&#x27;)</code></pre><button class="copy" data-copy="logging.error(&#x27;Failed&#x27;)">COPY</button></div><p>Error message</p></article><article class="card" data-search="logging &amp; cli logging.exception(&#x27;operation failed&#x27;) log exception traceback"><div class="cmdrow"><pre><code>logging.exception(&#x27;Operation failed&#x27;)</code></pre><button class="copy" data-copy="logging.exception(&#x27;Operation failed&#x27;)">COPY</button></div><p>Log exception traceback</p></article><article class="card" data-search="logging &amp; cli logger = logging.getlogger(__name__) create module logger"><div class="cmdrow"><pre><code>logger = logging.getLogger(__name__)</code></pre><button class="copy" data-copy="logger = logging.getLogger(__name__)">COPY</button></div><p>Create module logger</p></article><article class="card" data-search="logging &amp; cli import argparse import argparse"><div class="cmdrow"><pre><code>import argparse</code></pre><button class="copy" data-copy="import argparse">COPY</button></div><p>Import argparse</p></article><article class="card" data-search="logging &amp; cli parser = argparse.argumentparser() create parser"><div class="cmdrow"><pre><code>parser = argparse.ArgumentParser()</code></pre><button class="copy" data-copy="parser = argparse.ArgumentParser()">COPY</button></div><p>Create parser</p></article><article class="card" data-search="logging &amp; cli parser.add_argument(&#x27;filename&#x27;) add positional argument"><div class="cmdrow"><pre><code>parser.add_argument(&#x27;filename&#x27;)</code></pre><button class="copy" data-copy="parser.add_argument(&#x27;filename&#x27;)">COPY</button></div><p>Add positional argument</p></article><article class="card" data-search="logging &amp; cli parser.add_argument(&#x27;-v&#x27;, &#x27;--verbose&#x27;, action=&#x27;store_true&#x27;) add boolean flag"><div class="cmdrow"><pre><code>parser.add_argument(&#x27;-v&#x27;, &#x27;--verbose&#x27;, action=&#x27;store_true&#x27;)</code></pre><button class="copy" data-copy="parser.add_argument(&#x27;-v&#x27;, &#x27;--verbose&#x27;, action=&#x27;store_true&#x27;)">COPY</button></div><p>Add boolean flag</p></article><article class="card" data-search="logging &amp; cli parser.add_argument(&#x27;--count&#x27;, type=int, default=1) add typed optional argument"><div class="cmdrow"><pre><code>parser.add_argument(&#x27;--count&#x27;, type=int, default=1)</code></pre><button class="copy" data-copy="parser.add_argument(&#x27;--count&#x27;, type=int, default=1)">COPY</button></div><p>Add typed optional argument</p></article><article class="card" data-search="logging &amp; cli args = parser.parse_args() parse cli arguments"><div class="cmdrow"><pre><code>args = parser.parse_args()</code></pre><button class="copy" data-copy="args = parser.parse_args()">COPY</button></div><p>Parse CLI arguments</p></article><article class="card" data-search="logging &amp; cli args.filename access parsed argument"><div class="cmdrow"><pre><code>args.filename</code></pre><button class="copy" data-copy="args.filename">COPY</button></div><p>Access parsed argument</p></article></div></div></section><section class="section" id="asyncio---concurrency"><button class="sectionhead"><span>Asyncio &amp; Concurrency</span><small>17 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="asyncio &amp; concurrency import asyncio import asyncio"><div class="cmdrow"><pre><code>import asyncio</code></pre><button class="copy" data-copy="import asyncio">COPY</button></div><p>Import asyncio</p></article><article class="card" data-search="asyncio &amp; concurrency async def main():
224 ... define coroutine"><div class="cmdrow"><pre><code>async def main():
225 ...</code></pre><button class="copy" data-copy="async def main():
226 ...">COPY</button></div><p>Define coroutine</p></article><article class="card" data-search="asyncio &amp; concurrency await asyncio.sleep(1) non-blocking sleep"><div class="cmdrow"><pre><code>await asyncio.sleep(1)</code></pre><button class="copy" data-copy="await asyncio.sleep(1)">COPY</button></div><p>Non-blocking sleep</p></article><article class="card" data-search="asyncio &amp; concurrency asyncio.run(main()) run top-level coroutine"><div class="cmdrow"><pre><code>asyncio.run(main())</code></pre><button class="copy" data-copy="asyncio.run(main())">COPY</button></div><p>Run top-level coroutine</p></article><article class="card" data-search="asyncio &amp; concurrency task = asyncio.create_task(coro()) schedule coroutine"><div class="cmdrow"><pre><code>task = asyncio.create_task(coro())</code></pre><button class="copy" data-copy="task = asyncio.create_task(coro())">COPY</button></div><p>Schedule coroutine</p></article><article class="card" data-search="asyncio &amp; concurrency await task wait for task"><div class="cmdrow"><pre><code>await task</code></pre><button class="copy" data-copy="await task">COPY</button></div><p>Wait for task</p></article><article class="card" data-search="asyncio &amp; concurrency await asyncio.gather(coro1(), coro2()) run multiple awaitables concurrently"><div class="cmdrow"><pre><code>await asyncio.gather(coro1(), coro2())</code></pre><button class="copy" data-copy="await asyncio.gather(coro1(), coro2())">COPY</button></div><p>Run multiple awaitables concurrently</p></article><article class="card" data-search="asyncio &amp; concurrency from threading import thread import thread"><div class="cmdrow"><pre><code>from threading import Thread</code></pre><button class="copy" data-copy="from threading import Thread">COPY</button></div><p>Import Thread</p></article><article class="card" data-search="asyncio &amp; concurrency t = thread(target=func, args=(value,)) create a thread"><div class="cmdrow"><pre><code>t = Thread(target=func, args=(value,))</code></pre><button class="copy" data-copy="t = Thread(target=func, args=(value,))">COPY</button></div><p>Create a thread</p></article><article class="card" data-search="asyncio &amp; concurrency t.start() start thread"><div class="cmdrow"><pre><code>t.start()</code></pre><button class="copy" data-copy="t.start()">COPY</button></div><p>Start thread</p></article><article class="card" data-search="asyncio &amp; concurrency t.join() wait for thread"><div class="cmdrow"><pre><code>t.join()</code></pre><button class="copy" data-copy="t.join()">COPY</button></div><p>Wait for thread</p></article><article class="card" data-search="asyncio &amp; concurrency from concurrent.futures import threadpoolexecutor import thread pool"><div class="cmdrow"><pre><code>from concurrent.futures import ThreadPoolExecutor</code></pre><button class="copy" data-copy="from concurrent.futures import ThreadPoolExecutor">COPY</button></div><p>Import thread pool</p></article><article class="card" data-search="asyncio &amp; concurrency with threadpoolexecutor() as ex:
227 results = list(ex.map(func, items)) map work across threads"><div class="cmdrow"><pre><code>with ThreadPoolExecutor() as ex:
228 results = list(ex.map(func, items))</code></pre><button class="copy" data-copy="with ThreadPoolExecutor() as ex:
229 results = list(ex.map(func, items))">COPY</button></div><p>Map work across threads</p></article><article class="card" data-search="asyncio &amp; concurrency from multiprocessing import process import process"><div class="cmdrow"><pre><code>from multiprocessing import Process</code></pre><button class="copy" data-copy="from multiprocessing import Process">COPY</button></div><p>Import Process</p></article><article class="card" data-search="asyncio &amp; concurrency p = process(target=func) create child process"><div class="cmdrow"><pre><code>p = Process(target=func)</code></pre><button class="copy" data-copy="p = Process(target=func)">COPY</button></div><p>Create child process</p></article><article class="card" data-search="asyncio &amp; concurrency p.start(); p.join() start and wait for process"><div class="cmdrow"><pre><code>p.start(); p.join()</code></pre><button class="copy" data-copy="p.start(); p.join()">COPY</button></div><p>Start and wait for process</p></article><article class="card" data-search="asyncio &amp; concurrency from concurrent.futures import processpoolexecutor import process pool"><div class="cmdrow"><pre><code>from concurrent.futures import ProcessPoolExecutor</code></pre><button class="copy" data-copy="from concurrent.futures import ProcessPoolExecutor">COPY</button></div><p>Import process pool</p></article></div></div></section><section class="section" id="sqlite"><button class="sectionhead"><span>Sqlite</span><small>10 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="sqlite import sqlite3 import sqlite"><div class="cmdrow"><pre><code>import sqlite3</code></pre><button class="copy" data-copy="import sqlite3">COPY</button></div><p>Import SQLite</p></article><article class="card" data-search="sqlite conn = sqlite3.connect(&#x27;app.db&#x27;) open or create database"><div class="cmdrow"><pre><code>conn = sqlite3.connect(&#x27;app.db&#x27;)</code></pre><button class="copy" data-copy="conn = sqlite3.connect(&#x27;app.db&#x27;)">COPY</button></div><p>Open or create database</p></article><article class="card" data-search="sqlite cur = conn.cursor() create cursor"><div class="cmdrow"><pre><code>cur = conn.cursor()</code></pre><button class="copy" data-copy="cur = conn.cursor()">COPY</button></div><p>Create cursor</p></article><article class="card" data-search="sqlite cur.execute(&#x27;create table if not exists users (id integer primary key, name text)&#x27;) create table"><div class="cmdrow"><pre><code>cur.execute(&#x27;CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY, name TEXT)&#x27;)</code></pre><button class="copy" data-copy="cur.execute(&#x27;CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY, name TEXT)&#x27;)">COPY</button></div><p>Create table</p></article><article class="card" data-search="sqlite cur.execute(&#x27;insert into users(name) values (?)&#x27;, (&#x27;ada&#x27;,)) insert with parameters"><div class="cmdrow"><pre><code>cur.execute(&#x27;INSERT INTO users(name) VALUES (?)&#x27;, (&#x27;Ada&#x27;,))</code></pre><button class="copy" data-copy="cur.execute(&#x27;INSERT INTO users(name) VALUES (?)&#x27;, (&#x27;Ada&#x27;,))">COPY</button></div><p>Insert with parameters</p></article><article class="card" data-search="sqlite conn.commit() commit transaction"><div class="cmdrow"><pre><code>conn.commit()</code></pre><button class="copy" data-copy="conn.commit()">COPY</button></div><p>Commit transaction</p></article><article class="card" data-search="sqlite cur.execute(&#x27;select * from users&#x27;) run select"><div class="cmdrow"><pre><code>cur.execute(&#x27;SELECT * FROM users&#x27;)</code></pre><button class="copy" data-copy="cur.execute(&#x27;SELECT * FROM users&#x27;)">COPY</button></div><p>Run SELECT</p></article><article class="card" data-search="sqlite rows = cur.fetchall() fetch all rows"><div class="cmdrow"><pre><code>rows = cur.fetchall()</code></pre><button class="copy" data-copy="rows = cur.fetchall()">COPY</button></div><p>Fetch all rows</p></article><article class="card" data-search="sqlite conn.close() close connection"><div class="cmdrow"><pre><code>conn.close()</code></pre><button class="copy" data-copy="conn.close()">COPY</button></div><p>Close connection</p></article><article class="card" data-search="sqlite with sqlite3.connect(&#x27;app.db&#x27;) as conn:
230 conn.execute(...) use database context manager"><div class="cmdrow"><pre><code>with sqlite3.connect(&#x27;app.db&#x27;) as conn:
231 conn.execute(...)</code></pre><button class="copy" data-copy="with sqlite3.connect(&#x27;app.db&#x27;) as conn:
232 conn.execute(...)">COPY</button></div><p>Use database context manager</p></article></div></div></section><section class="section" id="testing"><button class="sectionhead"><span>Testing</span><small>7 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="testing import unittest import unittest"><div class="cmdrow"><pre><code>import unittest</code></pre><button class="copy" data-copy="import unittest">COPY</button></div><p>Import unittest</p></article><article class="card" data-search="testing class testmath(unittest.testcase):
233 def test_add(self):
234 self.assertequal(1 + 1, 2) define a unit test"><div class="cmdrow"><pre><code>class TestMath(unittest.TestCase):
235 def test_add(self):
236 self.assertEqual(1 + 1, 2)</code></pre><button class="copy" data-copy="class TestMath(unittest.TestCase):
237 def test_add(self):
238 self.assertEqual(1 + 1, 2)">COPY</button></div><p>Define a unit test</p></article><article class="card" data-search="testing python -m unittest discover and run unittest tests"><div class="cmdrow"><pre><code>python -m unittest</code></pre><button class="copy" data-copy="python -m unittest">COPY</button></div><p>Discover and run unittest tests</p></article><article class="card" data-search="testing self.asserttrue(value) assert truth"><div class="cmdrow"><pre><code>self.assertTrue(value)</code></pre><button class="copy" data-copy="self.assertTrue(value)">COPY</button></div><p>Assert truth</p></article><article class="card" data-search="testing self.assertequal(a, b) assert equality"><div class="cmdrow"><pre><code>self.assertEqual(a, b)</code></pre><button class="copy" data-copy="self.assertEqual(a, b)">COPY</button></div><p>Assert equality</p></article><article class="card" data-search="testing self.assertraises(valueerror) assert exception"><div class="cmdrow"><pre><code>self.assertRaises(ValueError)</code></pre><button class="copy" data-copy="self.assertRaises(ValueError)">COPY</button></div><p>Assert exception</p></article><article class="card" data-search="testing python -m doctest file.py run doctests"><div class="cmdrow"><pre><code>python -m doctest file.py</code></pre><button class="copy" data-copy="python -m doctest file.py">COPY</button></div><p>Run doctests</p></article></div></div></section><section class="section" id="http-requests---third-party"><button class="sectionhead"><span>Http Requests — Third Party</span><small>8 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="http requests — third party python -m pip install requests install requests"><div class="cmdrow"><pre><code>python -m pip install requests</code></pre><button class="copy" data-copy="python -m pip install requests">COPY</button></div><p>Install Requests</p></article><article class="card" data-search="http requests — third party import requests import requests"><div class="cmdrow"><pre><code>import requests</code></pre><button class="copy" data-copy="import requests">COPY</button></div><p>Import Requests</p></article><article class="card" data-search="http requests — third party r = requests.get(&#x27;https://example.com&#x27;, timeout=10) http get request"><div class="cmdrow"><pre><code>r = requests.get(&#x27;https://example.com&#x27;, timeout=10)</code></pre><button class="copy" data-copy="r = requests.get(&#x27;https://example.com&#x27;, timeout=10)">COPY</button></div><p>HTTP GET request</p></article><article class="card" data-search="http requests — third party r.status_code read status code"><div class="cmdrow"><pre><code>r.status_code</code></pre><button class="copy" data-copy="r.status_code">COPY</button></div><p>Read status code</p></article><article class="card" data-search="http requests — third party r.text read response text"><div class="cmdrow"><pre><code>r.text</code></pre><button class="copy" data-copy="r.text">COPY</button></div><p>Read response text</p></article><article class="card" data-search="http requests — third party r.json() decode json response"><div class="cmdrow"><pre><code>r.json()</code></pre><button class="copy" data-copy="r.json()">COPY</button></div><p>Decode JSON response</p></article><article class="card" data-search="http requests — third party requests.post(url, json=data, timeout=10) post json data"><div class="cmdrow"><pre><code>requests.post(url, json=data, timeout=10)</code></pre><button class="copy" data-copy="requests.post(url, json=data, timeout=10)">COPY</button></div><p>POST JSON data</p></article><article class="card" data-search="http requests — third party r.raise_for_status() raise on http error"><div class="cmdrow"><pre><code>r.raise_for_status()</code></pre><button class="copy" data-copy="r.raise_for_status()">COPY</button></div><p>Raise on HTTP error</p></article></div></div></section><section class="section" id="useful-built-ins---one-liners"><button class="sectionhead"><span>Useful Built-Ins &amp; One-Liners</span><small>22 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="useful built-ins &amp; one-liners len(obj) number of items"><div class="cmdrow"><pre><code>len(obj)</code></pre><button class="copy" data-copy="len(obj)">COPY</button></div><p>Number of items</p></article><article class="card" data-search="useful built-ins &amp; one-liners sorted(iterable) return sorted list"><div class="cmdrow"><pre><code>sorted(iterable)</code></pre><button class="copy" data-copy="sorted(iterable)">COPY</button></div><p>Return sorted list</p></article><article class="card" data-search="useful built-ins &amp; one-liners reversed(sequence) reverse iterator"><div class="cmdrow"><pre><code>reversed(sequence)</code></pre><button class="copy" data-copy="reversed(sequence)">COPY</button></div><p>Reverse iterator</p></article><article class="card" data-search="useful built-ins &amp; one-liners enumerate(iterable) pair with indexes"><div class="cmdrow"><pre><code>enumerate(iterable)</code></pre><button class="copy" data-copy="enumerate(iterable)">COPY</button></div><p>Pair with indexes</p></article><article class="card" data-search="useful built-ins &amp; one-liners zip(a, b) pair multiple iterables"><div class="cmdrow"><pre><code>zip(a, b)</code></pre><button class="copy" data-copy="zip(a, b)">COPY</button></div><p>Pair multiple iterables</p></article><article class="card" data-search="useful built-ins &amp; one-liners all(values) true if all are truthy"><div class="cmdrow"><pre><code>all(values)</code></pre><button class="copy" data-copy="all(values)">COPY</button></div><p>True if all are truthy</p></article><article class="card" data-search="useful built-ins &amp; one-liners any(values) true if any are truthy"><div class="cmdrow"><pre><code>any(values)</code></pre><button class="copy" data-copy="any(values)">COPY</button></div><p>True if any are truthy</p></article><article class="card" data-search="useful built-ins &amp; one-liners min(values) smallest value"><div class="cmdrow"><pre><code>min(values)</code></pre><button class="copy" data-copy="min(values)">COPY</button></div><p>Smallest value</p></article><article class="card" data-search="useful built-ins &amp; one-liners max(values) largest value"><div class="cmdrow"><pre><code>max(values)</code></pre><button class="copy" data-copy="max(values)">COPY</button></div><p>Largest value</p></article><article class="card" data-search="useful built-ins &amp; one-liners sum(values) sum numeric values"><div class="cmdrow"><pre><code>sum(values)</code></pre><button class="copy" data-copy="sum(values)">COPY</button></div><p>Sum numeric values</p></article><article class="card" data-search="useful built-ins &amp; one-liners set(iterable) create set"><div class="cmdrow"><pre><code>set(iterable)</code></pre><button class="copy" data-copy="set(iterable)">COPY</button></div><p>Create set</p></article><article class="card" data-search="useful built-ins &amp; one-liners list(iterable) create list"><div class="cmdrow"><pre><code>list(iterable)</code></pre><button class="copy" data-copy="list(iterable)">COPY</button></div><p>Create list</p></article><article class="card" data-search="useful built-ins &amp; one-liners tuple(iterable) create tuple"><div class="cmdrow"><pre><code>tuple(iterable)</code></pre><button class="copy" data-copy="tuple(iterable)">COPY</button></div><p>Create tuple</p></article><article class="card" data-search="useful built-ins &amp; one-liners dict(pairs) create dictionary"><div class="cmdrow"><pre><code>dict(pairs)</code></pre><button class="copy" data-copy="dict(pairs)">COPY</button></div><p>Create dictionary</p></article><article class="card" data-search="useful built-ins &amp; one-liners numbers = [int(x) for x in input().split()] read space-separated integers"><div class="cmdrow"><pre><code>numbers = [int(x) for x in input().split()]</code></pre><button class="copy" data-copy="numbers = [int(x) for x in input().split()]">COPY</button></div><p>Read space-separated integers</p></article><article class="card" data-search="useful built-ins &amp; one-liners unique = list(dict.fromkeys(items)) remove duplicates while preserving order"><div class="cmdrow"><pre><code>unique = list(dict.fromkeys(items))</code></pre><button class="copy" data-copy="unique = list(dict.fromkeys(items))">COPY</button></div><p>Remove duplicates while preserving order</p></article><article class="card" data-search="useful built-ins &amp; one-liners flat = [x for row in matrix for x in row] flatten one level"><div class="cmdrow"><pre><code>flat = [x for row in matrix for x in row]</code></pre><button class="copy" data-copy="flat = [x for row in matrix for x in row]">COPY</button></div><p>Flatten one level</p></article><article class="card" data-search="useful built-ins &amp; one-liners largest = max(items, key=len) find longest item"><div class="cmdrow"><pre><code>largest = max(items, key=len)</code></pre><button class="copy" data-copy="largest = max(items, key=len)">COPY</button></div><p>Find longest item</p></article><article class="card" data-search="useful built-ins &amp; one-liners sorted_users = sorted(users, key=lambda u: u[&#x27;name&#x27;]) sort dictionaries by a field"><div class="cmdrow"><pre><code>sorted_users = sorted(users, key=lambda u: u[&#x27;name&#x27;])</code></pre><button class="copy" data-copy="sorted_users = sorted(users, key=lambda u: u[&#x27;name&#x27;])">COPY</button></div><p>Sort dictionaries by a field</p></article><article class="card" data-search="useful built-ins &amp; one-liners pairs = dict(zip(keys, values)) build dictionary from two sequences"><div class="cmdrow"><pre><code>pairs = dict(zip(keys, values))</code></pre><button class="copy" data-copy="pairs = dict(zip(keys, values))">COPY</button></div><p>Build dictionary from two sequences</p></article><article class="card" data-search="useful built-ins &amp; one-liners text = &#x27; &#x27;.join(text.split()) normalize whitespace"><div class="cmdrow"><pre><code>text = &#x27; &#x27;.join(text.split())</code></pre><button class="copy" data-copy="text = &#x27; &#x27;.join(text.split())">COPY</button></div><p>Normalize whitespace</p></article><article class="card" data-search="useful built-ins &amp; one-liners next((x for x in items if predicate(x)), none) get first match or none"><div class="cmdrow"><pre><code>next((x for x in items if predicate(x)), None)</code></pre><button class="copy" data-copy="next((x for x in items if predicate(x)), None)">COPY</button></div><p>Get first match or None</p></article></div></div></section><section class="section" id="common-pitfalls"><button class="sectionhead"><span>Common Pitfalls</span><small>8 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="common pitfalls if value == none: prefer `is none` for none checks"><div class="cmdrow"><pre><code>if value == None:</code></pre><button class="copy" data-copy="if value == None:">COPY</button></div><p>Prefer `is None` for None checks</p></article><article class="card" data-search="common pitfalls from module import * avoid wildcard imports in normal application code"><div class="cmdrow"><pre><code>from module import *</code></pre><button class="copy" data-copy="from module import *">COPY</button></div><p>Avoid wildcard imports in normal application code</p></article><article class="card" data-search="common pitfalls except: prefer catching specific exception types"><div class="cmdrow"><pre><code>except:</code></pre><button class="copy" data-copy="except:">COPY</button></div><p>Prefer catching specific exception types</p></article><article class="card" data-search="common pitfalls a = [[0] * 3] * 3 nested list multiplication shares inner lists"><div class="cmdrow"><pre><code>a = [[0] * 3] * 3</code></pre><button class="copy" data-copy="a = [[0] * 3] * 3">COPY</button></div><p>Nested list multiplication shares inner lists</p></article><article class="card" data-search="common pitfalls 0.1 + 0.2 == 0.3 floating-point values are approximate"><div class="cmdrow"><pre><code>0.1 + 0.2 == 0.3</code></pre><button class="copy" data-copy="0.1 + 0.2 == 0.3">COPY</button></div><p>Floating-point values are approximate</p></article><article class="card" data-search="common pitfalls items.sort() sort() modifies a list and returns none"><div class="cmdrow"><pre><code>items.sort()</code></pre><button class="copy" data-copy="items.sort()">COPY</button></div><p>sort() modifies a list and returns None</p></article><article class="card" data-search="common pitfalls print(func()) a function that only prints usually returns none"><div class="cmdrow"><pre><code>print(func())</code></pre><button class="copy" data-copy="print(func())">COPY</button></div><p>A function that only prints usually returns None</p></article><article class="card" data-search="common pitfalls def add(x, bucket=[]):
239 bucket.append(x)
240 return bucket avoid mutable default arguments; use none and create the list inside"><div class="cmdrow"><pre><code>def add(x, bucket=[]):
241 bucket.append(x)
242 return bucket</code></pre><button class="copy" data-copy="def add(x, bucket=[]):
243 bucket.append(x)
244 return bucket">COPY</button></div><p>Avoid mutable default arguments; use None and create the list inside</p></article></div></div></section><section class="section" id="formatting---code-quality"><button class="sectionhead"><span>Formatting &amp; Code Quality</span><small>7 snippets</small><b>▾</b></button><div class="body"><div class="grid"><article class="card" data-search="formatting &amp; code quality python -m py_compile file.py compile one file and catch syntax errors"><div class="cmdrow"><pre><code>python -m py_compile file.py</code></pre><button class="copy" data-copy="python -m py_compile file.py">COPY</button></div><p>Compile one file and catch syntax errors</p></article><article class="card" data-search="formatting &amp; code quality python -m compileall . compile a project and catch syntax errors"><div class="cmdrow"><pre><code>python -m compileall .</code></pre><button class="copy" data-copy="python -m compileall .">COPY</button></div><p>Compile a project and catch syntax errors</p></article><article class="card" data-search="formatting &amp; code quality python -m pip install black install black"><div class="cmdrow"><pre><code>python -m pip install black</code></pre><button class="copy" data-copy="python -m pip install black">COPY</button></div><p>Install Black</p></article><article class="card" data-search="formatting &amp; code quality python -m black file.py format with black"><div class="cmdrow"><pre><code>python -m black file.py</code></pre><button class="copy" data-copy="python -m black file.py">COPY</button></div><p>Format with Black</p></article><article class="card" data-search="formatting &amp; code quality python -m pip install ruff install ruff"><div class="cmdrow"><pre><code>python -m pip install ruff</code></pre><button class="copy" data-copy="python -m pip install ruff">COPY</button></div><p>Install Ruff</p></article><article class="card" data-search="formatting &amp; code quality python -m ruff check . lint with ruff"><div class="cmdrow"><pre><code>python -m ruff check .</code></pre><button class="copy" data-copy="python -m ruff check .">COPY</button></div><p>Lint with Ruff</p></article><article class="card" data-search="formatting &amp; code quality python -m ruff format . format with ruff"><div class="cmdrow"><pre><code>python -m ruff format .</code></pre><button class="copy" data-copy="python -m ruff format .">COPY</button></div><p>Format with Ruff</p></article></div></div></section></main></div>
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