first steps towards packages chapter

Author: thomasWeise

styles/listing.sty

@@ -256,7 +256,7 @@ breaklines=true%
 \protected\gdef\gitPythonAndOutputFormatDefault{\gitPythonAndOutputFormat{text_style}}%
 \gitPythonAndOutputFormatDefault%
 %
-%% Use latexgit to place a listing with code and the program output.
+%% Use latexgit to place a listing with Python code and the program output.
 %% #1 the git repository
 %% #2 the path to the directory
 %% #3 the path to the file inside the directory
@@ -285,6 +285,32 @@ $\downarrow$~~\expandafter\bashil{python3 #3}~~$\downarrow$%
 \end{figure}%
 }%
 %
+%% Use latexgit to place a listing with Bash code and the program output.
+%% #1 the git repository
+%% #2 the path to the directory
+%% #3 the path to the file inside the directory
+%% #4 the label (lst: will be prepended to the program, exec: will be
+%%    pre-pended to the output)
+%% #5 the caption
+\protected\gdef\gitBashAndOutput#1#2#3#4#5{%
+%
+\gitLoad{#1}{#2/#3}{}%
+\expandafter\expandafter\expandafter\edef\expandafter\csname @pwp@gitUrl:lst:#4\endcsname{\gitUrl}%
+\expandafter\expandafter\expandafter\edef\expandafter\csname @pwp@gitFile:lst:#4\endcsname{\gitFile}%
+\gitExec{#1}{#2}{bash #3}%
+\expandafter\expandafter\expandafter\edef\expandafter\csname @pwp@gitFile:exec:#4\endcsname{\gitFile}%
+%
+\begin{figure}[tb]%
+\centering%
+\lstinputlisting[label={lst:#4},style=bash_style,caption={#5~(stored in file~\href{\csname @pwp@gitUrl:lst:#4\endcsname}{\textil{#3}}; output in~\cref{exec:#4})}]{\csname @pwp@gitFile:lst:#4\endcsname}%
+%
+$\downarrow$~~\expandafter\bashil{bash #3}~~$\downarrow$%
+%
+\edef\@@@@gitOutputFmt{\csname @gitPythonAndOutputFormat:exec:#4\endcsname}%
+\lstinputlisting[label={exec:#4},style=tool_style,caption={The \gls{stdout} of the program~\href{\csname @pwp@gitUrl:lst:#4\endcsname}{\textil{#3}} given in~\cref{lst:#4}.}]{\csname @pwp@gitFile:exec:#4\endcsname}%
+\end{figure}%
+}%
+%
 %
 %% Use latexgit to place a listing with code and the program output.
 %% Ignore errors.

text/main/mainmatter.tex

@@ -6,4 +6,5 @@
 \hinput{basics}{basics.tex}%
 \hinput{controlFlow}{controlFlow.tex}%
 \hinput{classes}{classes.tex}%
+\hinput{packages}{packages.tex}%
 %

text/main/packages/packages.tex

@@ -0,0 +1,19 @@
+%
+\hsection{Packages}%
+%
+\begin{figure}%
+\centering%
+\includegraphics[width=0.68\linewidth]{\currentDir/pypi}%
+\caption{A screenshot of the website \url{https://pypi.org}, the \python\ Package Index~\cite{PSF2024TPPIP}, taken on \mbox{2024-12-24}.}%
+\label{fig:pypi}%
+\end{figure}%
+%
+As already mentioned very early on in this book, one important strength of \python\ is the wide range of available packages.
+A package in \python\ is a piece of software, a library, that bundles some functionality and that can be installed on a system to make that functionality usable.
+Many of these packages are open source software and they are available for anyone to use, free of charge.
+The number one source for such packages is the \python\ Package Index~\cite{PSF2024TPPIP}, a website from which they can be downloaded and installed, illustrated in \cref{fig:pypi}.
+In this section of the book, we will focus on how we can obtain and use packages.%
+%
+\hinput{pipAndVenv}{pipAndVenv.tex}%
+\endhsection%
+%

text/main/packages/pipAndVenv/installPipVenvUbuntu.pdf

@@ -0,0 +1,34 @@
+%
+\hsection{Pip and Virtual Environments}%
+%
+The go-to tool for installing \python\ packages is \pip.
+The standard way to install packages for use with \python\ is in a so-called virtual environment.
+%
+\hsection{Pip and Virtual Environments in \ubuntu\ \linux}%
+%
+\begin{figure}%
+\centering%
+\includegraphics[width=0.7\linewidth]{\currentDir/installPipVenvUbuntu}%
+\caption{Installing \pip\ and venv under \ubuntu\ \linux: \pip~is usually already installed, venv not. %
+We need to use the \bashil{apt-get} route to make sure that both \bashil{python3-pip} and \bashil{python3-venv} are installed.}%
+\label{fig:installPipVenvUbuntu}%
+\end{figure}%
+%
+\gitBashAndOutput{\programmingWithPythonCodeRepo}{10_packages}{numpy_user_venv.sh}{packages:numpy_user_venv}{%
+An example of using virtual environments and \pip\ under \ubuntu\ \linux.}%
+%
+\endhsection%
+%
+\hsection{Pip and Virtual Environments under \windows}%
+%
+\begin{figure}%
+\centering%
+\tightbox{\includegraphics[width=0.85\linewidth]{\currentDir/installPipVenvWindows}}%
+\caption{Installing \pip\ and venv under \windows: They are already installed.}%
+\label{fig:installPipVenvWindows}%
+\end{figure}%
+\endhsection%
+%
+\FloatBarrier%
+\endhsection%
+%