* **Module [operator](#operator) provides functions itemgetter() and mul() that offer the same functionality as [lambda](#lambda) expressions above.**

<int> = <list>.count(<el>) # Returns number of occurrences. Also works on strings.

<int> = <list>.index(<el>) # Returns index of the first occurrence or raises ValueError.

<list>.remove(<el>) # Removes first occurrence of the item or raises ValueError.

<list>.clear() # Removes all items. Also works on dictionary and set.

<Exec> = ThreadPoolExecutor(max_workers=None) # Or: `with ThreadPoolExecutor() as <name>: …`

sorted_by_both = sorted(<collection>, key=op.itemgetter(1, 0))

product_of_elems = functools.reduce(op.mul, <collection>)

union_of_sets = functools.reduce(op.or_, <coll_of_sets>)

last_el = op.methodcaller('pop')(<list>)

>>> data = {'team': 'arsenal f.c.'}

>>> response = requests.post(url, data=data)

>>> response.json()

with wave.open(filename, 'rb') as file:

sampwidth = file.getsampwidth()

frames = file.readframes(-1)

return [get_int(b) / pow(2, sampwidth * 8 - 1) for b in bytes_samples]

sin_f = lambda i, hz: math.sin(i * 2 * math.pi * hz / F)

get_wave = lambda hz, seconds: (sin_f(i, hz) for i in range(int(seconds * F)))

get_hz = lambda key: 8.176 * 2 ** (int(key) / 12)

samples_f = chain.from_iterable(get_samples(n) for n in f'{P1}{P1}{P2}'.split(','))

samples_b = b''.join(struct.pack('<h', int(f * 30000)) for f in samples_f)

simpleaudio.play_buffer(samples_b, 1, 2, F)

line(<Surf>, color, (x1, y1), (x2, y2), width) # Draws a line to the surface.

arc(<Surf>, color, <Rect>, from_rad, to_rad) # Also: ellipse(<Surf>, color, <Rect>)

rect(<Surf>, color, <Rect>) # Also: polygon(<Surf>, color, points)

Index

* **Ctrl+F / ⌘F is usually sufficient.**

* **Searching `'#<title>'` on a [webpage](https://gto76.github.io/python-cheatsheet/) will limit the search to the titles.**

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<div><h1 id="comprehensivepythoncheatsheet">Comprehensive Python Cheatsheet</h1><p class="banner"><sup><a href="https://raw.githubusercontent.com/gto76/python-cheatsheet/master/README.md">Download text file</a>, <a href="https://transactions.sendowl.com/products/78175486/4422834F/view">Buy PDF</a>, <a href="https://github.com/gto76/python-cheatsheet">Fork me on GitHub</a> or <a href="https://github.com/gto76/python-cheatsheet/wiki/Frequently-Asked-Questions">Check out FAQ</a>.

<strong><span class="hljs-string"><span class="hljs-string">'1. Collections'</span></span></strong>: [<a href="#list">List</a>, <a href="#dictionary">Dictionary</a>, <a href="#set">Set</a>, <a href="#tuple">Tuple</a>, <a href="#range">Range</a>, <a href="#enumerate">Enumerate</a>, <a href="#iterator">Iterator</a>, <a href="#generator">Generator</a>],

<strong><span class="hljs-string"><span class="hljs-string">'2. Types'</span></span></strong>: [<a href="#type">Type</a>, <a href="#string">String</a>, <a href="#regex">Regular_Exp</a>, <a href="#format">Format</a>, <a href="#numbers">Numbers</a>, <a href="#combinatorics">Combinatorics</a>, <a href="#datetime">Datetime</a>],

<strong><span class="hljs-string"><span class="hljs-string">'3. Syntax'</span></span></strong>: [<a href="#arguments">Args</a>, <a href="#inline">Inline</a>, <a href="#closure">Closure</a>, <a href="#decorator">Decorator</a>, <a href="#class">Class</a>, <a href="#ducktypes">Duck_Type</a>, <a href="#enum">Enum</a>, <a href="#exceptions">Exception</a>],

<li><strong>Module <a href="#operator">operator</a> provides functions itemgetter() and mul() that offer the same functionality as <a href="#lambda">lambda</a> expressions above.</strong></li>

&lt;int&gt; = &lt;list&gt;.index(&lt;el&gt;) <span class="hljs-comment"># Returns index of the first occurrence or raises ValueError.</span>

&lt;list&gt;.remove(&lt;el&gt;) <span class="hljs-comment"># Removes first occurrence of the item or raises ValueError.</span>

&lt;list&gt;.clear() <span class="hljs-comment"># Removes all items. Also works on dictionary and set.</span>

<pre><code class="python language-python hljs">&lt;Exec&gt; = ThreadPoolExecutor(max_workers=<span class="hljs-keyword">None</span>) <span class="hljs-comment"># Or: `with ThreadPoolExecutor() as &lt;name&gt;: …`</span>

<pre><code class="python language-python hljs">&lt;iter&gt; = &lt;Exec&gt;.map(&lt;func&gt;, &lt;args_1&gt;, ...) <span class="hljs-comment"># A multithreaded and non-lazy map().</span>

&lt;Futr&gt; = &lt;Exec&gt;.submit(&lt;func&gt;, &lt;arg_1&gt;, ...) <span class="hljs-comment"># Starts a thread and returns its Future object.</span>

sorted_by_both = sorted(&lt;collection&gt;, key=op.itemgetter(<span class="hljs-number">1</span>, <span class="hljs-number">0</span>))

product_of_elems = functools.reduce(op.mul, &lt;collection&gt;)

union_of_sets = functools.reduce(op.or_, &lt;coll_of_sets&gt;)

last_el = op.methodcaller(<span class="hljs-string">'pop'</span>)(&lt;list&gt;)

<div><h2 id="introspection"><a href="#introspection" name="introspection">#</a>Introspection</h2><p><strong>Inspecting code at runtime.</strong></p><div><h3 id="variables">Variables</h3><pre><code class="python language-python hljs">&lt;list&gt; = dir() <span class="hljs-comment"># Names of local variables (incl. functions).</span>

<div><h4 id="test">Test:</h4><pre><code class="python language-python hljs"><span class="hljs-comment"># $ pip3 install requests</span>

<span class="hljs-meta">&gt;&gt;&gt; </span>data = {<span class="hljs-string">'team'</span>: <span class="hljs-string">'arsenal f.c.'</span>}

<span class="hljs-meta">&gt;&gt;&gt; </span>response = requests.post(url, data=data)

<span class="hljs-meta">&gt;&gt;&gt; </span>response.json()

<span class="hljs-keyword">with</span> wave.open(filename, <span class="hljs-string">'rb'</span>) <span class="hljs-keyword">as</span> file:

sampwidth = file.getsampwidth()

frames = file.readframes(<span class="hljs-number">-1</span>)

<span class="hljs-keyword">return</span> [get_int(b) / pow(<span class="hljs-number">2</span>, sampwidth * <span class="hljs-number">8</span> - <span class="hljs-number">1</span>) <span class="hljs-keyword">for</span> b <span class="hljs-keyword">in</span> bytes_samples]

sin_f = <span class="hljs-keyword">lambda</span> i, hz: math.sin(i * <span class="hljs-number">2</span> * math.pi * hz / F)

get_wave = <span class="hljs-keyword">lambda</span> hz, seconds: (sin_f(i, hz) <span class="hljs-keyword">for</span> i <span class="hljs-keyword">in</span> range(int(seconds * F)))

get_hz = <span class="hljs-keyword">lambda</span> key: <span class="hljs-number">8.176</span> * <span class="hljs-number">2</span> ** (int(key) / <span class="hljs-number">12</span>)

samples_f = chain.from_iterable(get_samples(n) <span class="hljs-keyword">for</span> n <span class="hljs-keyword">in</span> <span class="hljs-string">f'<span class="hljs-subst">{P1}</span><span class="hljs-subst">{P1}</span><span class="hljs-subst">{P2}</span>'</span>.split(<span class="hljs-string">','</span>))

samples_b = <span class="hljs-string">b''</span>.join(struct.pack(<span class="hljs-string">'&lt;h'</span>, int(f * <span class="hljs-number">30000</span>)) <span class="hljs-keyword">for</span> f <span class="hljs-keyword">in</span> samples_f)

simpleaudio.play_buffer(samples_b, <span class="hljs-number">1</span>, <span class="hljs-number">2</span>, F)

&lt;Surf&gt;.set_at((x, y), color) <span class="hljs-comment"># Updates pixel.</span>

&lt;Surf&gt;.blit(&lt;Surf&gt;, (x, y)) <span class="hljs-comment"># Draws passed surface to the surface.</span>

line(&lt;Surf&gt;, color, (x1, y1), (x2, y2), width) <span class="hljs-comment"># Draws a line to the surface.</span>

arc(&lt;Surf&gt;, color, &lt;Rect&gt;, from_rad, to_rad) <span class="hljs-comment"># Also: ellipse(&lt;Surf&gt;, color, &lt;Rect&gt;)</span>

rect(&lt;Surf&gt;, color, &lt;Rect&gt;) <span class="hljs-comment"># Also: polygon(&lt;Surf&gt;, color, points)</span>

main()

<li><strong>Ctrl+F / ⌘F is usually sufficient.</strong></li>

<li><strong>Searching <code class="python hljs"><span class="hljs-string">'#&lt;title&gt;'</span></code> will limit the search to the titles.</strong></li>

const TOC =

'<br>' +

'<h2 id="toc">Contents</h2>\n' +

' <strong><span class="hljs-string">\'1. Collections\'</span></strong>: [<a href="#list">List</a>, <a href="#dictionary">Dictionary</a>, <a href="#set">Set</a>, <a href="#tuple">Tuple</a>, <a href="#range">Range</a>, <a href="#enumerate">Enumerate</a>, <a href="#iterator">Iterator</a>, <a href="#generator">Generator</a>],\n' +

' <strong><span class="hljs-string">\'2. Types\'</span></strong>: [<a href="#type">Type</a>, <a href="#string">String</a>, <a href="#regex">Regular_Exp</a>, <a href="#format">Format</a>, <a href="#numbers">Numbers</a>, <a href="#combinatorics">Combinatorics</a>, <a href="#datetime">Datetime</a>],\n' +

' <strong><span class="hljs-string">\'3. Syntax\'</span></strong>: [<a href="#arguments">Args</a>, <a href="#inline">Inline</a>, <a href="#closure">Closure</a>, <a href="#decorator">Decorator</a>, <a href="#class">Class</a>, <a href="#ducktypes">Duck_Type</a>, <a href="#enum">Enum</a>, <a href="#exceptions">Exception</a>],\n' +

'$ pyinstaller script.py --add-data \'&lt;path&gt;:.\' <span class="hljs-comment"># Adds file to the root of the executable.</span>\n';

const INDEX =

'<li><strong>Ctrl+F / ⌘F is usually sufficient.</strong></li>\n' +

'<li><strong>Searching <code class="python hljs"><span class="hljs-string">\'#&lt;title&gt;\'</span></code> will limit the search to the titles.</strong></li>\n';