\documentclass[10pt,a4paper]{article}

% Packages
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\usepackage{multicol}           % Allows multicols in tables
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\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
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\usepackage{colortbl}           % For coloured tables
\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{blakecromar}
\pdfinfo{
  /Title (python-standard-libraries.pdf)
  /Creator (Cheatography)
  /Author (blakecromar)
  /Subject (Python (Standard Libraries) Cheat Sheet)
}

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% This two commands together give roughly
% the right line height in the tables
\renewcommand{\arraystretch}{1.3}
\onehalfspacing

% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
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% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Python (Standard Libraries) Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{blakecromar} via \textcolor{DarkBackground}{\uline{cheatography.com/218070/cs/48252/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}blakecromar \\
  \uline{cheatography.com/blakecromar} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 1st July, 2026.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
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  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
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  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{3}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{@dataclass}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{from dataclasses import dataclass \newline  \newline @dataclass \newline class my\_class: \newline     field\_one: type\_one \newline     field\_two: type\_two \newline     field\_three: type\_three \newline  \newline \# automatically gets \_\_init\_\_, \_\_repr\_\_, and \_\_eq\_\_ \newline my\_instance = my\_class( \newline     field\_one=value\_one, \newline     field\_two=value\_two, \newline     \seqsplit{field\_three=value\_three} \newline )} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{A decorator that automatically generates \_\_init\_\_, \_\_repr\_\_, and \_\_eq\_\_ methods from class fields. \newline Each field is declared with its name and type annotation — no need to write a constructor manually. \newline Part of the standard library via from dataclasses import dataclass.}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{io}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{import io \newline  \newline \# in-memory binary stream \newline binary\_buffer = io.BytesIO(b"some bytes") \newline binary\_buffer.read()         \# read all bytes \newline binary\_buffer.read(4)        \# read exactly 4 bytes from cursor position \newline binary\_buffer.write(b"more") \# write bytes \newline binary\_buffer.seek(0)        \# move cursor back to start \newline  \newline \# in-memory text stream \newline text\_buffer = io.StringIO("some text") \newline text\_buffer.read()           \# read all text \newline text\_buffer.read(4)          \# read exactly 4 characters \newline text\_buffer.seek(0)          \# move cursor back to start} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{Python's standard library module for working with streams and file-like objects. \newline Provides in-memory file objects that behave exactly like real files but exist only in RAM. \newline BytesIO is for binary data, StringIO is for text data. \newline read(n) reads exactly n bytes from the current cursor position — useful for parsing binary formats where you need to read fixed-size chunks.}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{struct}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{import struct \newline  \newline \# endianness prefix \newline \# \textless{} = little-endian (least significant byte first, most common) \newline \# \textgreater{} = big-endian    (most significant byte first, used in network protocols) \newline  \newline \# type codes \newline \# b = int8     B = uint8 \newline \# h = int16    H = uint16 \newline \# i = int32    I = uint32 \newline \# q = int64    Q = uint64 \newline \# f = float32  d = float64 \newline \# s = char{[}{]}   ? = bool \newline  \newline \# repeating type codes — t = any type code \newline \# t = one value    tt = two values    ttt = three values \newline  \newline \# unpack — read bytes into Python values \newline value: int = struct.unpack("\textless{}i", f.read(4)){[}0{]}           \# read one int32 \newline a: int; b: int = struct.unpack("\textless{}ii", f.read(8))         \# read two int32s \newline three\_ints: tuple = struct.unpack("\textless{}iii", f.read(12))    \# read three int32s \newline  \newline \# pack — convert Python values into bytes \newline data: bytes = struct.pack("\textless{}i", 42)                      \# write one int32 \newline data: bytes = struct.pack("\textless{}ii", 42, 100)                \# write two int32s} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{Converts between Python values and C-style binary data using format strings. \newline struct.unpack(format, bytes) reads bytes and returns a tuple of Python values. \newline struct.pack(format, values) converts Python values into bytes.}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}