a good python ambient for my latex code

Question

I am looking for a latex preamble in order to have a good python script. Here I found this

\documentclass[a4paper,12pt]{article}
\usepackage[utf8]{inputenc}

% Default fixed font does not support bold face
\DeclareFixedFont{\ttb}{T1}{txtt}{bx}{n}{12} % for bold
\DeclareFixedFont{\ttm}{T1}{txtt}{m}{n}{12}  % for normal

% Custom colors
\usepackage{color}
\definecolor{deepblue}{rgb}{0,0,0.5}
\definecolor{deepred}{rgb}{0.6,0,0}
\definecolor{deepgreen}{rgb}{0,0.5,0}

\usepackage{listings}

% Python style for highlighting
\newcommand\pythonstyle{\lstset{
language=Python,
basicstyle=\ttm,
morekeywords={self},              % Add keywords here
keywordstyle=\ttb\color{deepblue},
emph={MyClass,__init__},          % Custom highlighting
emphstyle=\ttb\color{deepred},    % Custom highlighting style
stringstyle=\color{deepgreen},
frame=tb,                         % Any extra options here
showstringspaces=false
}}


% Python environment

which looks great but I find noway to apply it into my latex code, phereaps I'm lost into the complexity of it and what I am looking for is just a sample code such as

\begin{document}

here some python codes

\begin{listings}
    \pythonstyle 
import numpy as np
class __init__(self, a, b):
    self.a = a
    self.b = b
\end{listings}
\end{document}

or the like, in order to have a proper python ambient. Could you help me, please?

Answer 1

You're doing two things wrong:

1. the code environment of the listings package is not called listing, but lstlisting
2. the \pythonstyle macro should go before the code environment

So if you do

\pythonstyle 
\begin{lstlisting}
import numpy as np
class __init__(self, a, b):
    self.a = a
    self.b = b
\end{lstlisting}

it will work.

I do think it's a bit odd to define a macro like that, instead of for example defining a new listings style with \lstdefinestyle. See example below.

\documentclass[a4paper,12pt]{article}
\usepackage[utf8]{inputenc}

% Default fixed font does not support bold face
\DeclareFixedFont{\ttb}{T1}{txtt}{bx}{n}{12} % for bold
\DeclareFixedFont{\ttm}{T1}{txtt}{m}{n}{12}  % for normal

% Custom colors
\usepackage{color}
\definecolor{deepblue}{rgb}{0,0,0.5}
\definecolor{deepred}{rgb}{0.6,0,0}
\definecolor{deepgreen}{rgb}{0,0.5,0}

\usepackage{listings}

% Python style for highlighting
\newcommand\pythonstyle{\lstset{
language=Python,
literate={-}{-}1 {*}{*}1,% {xxx}{\textrm{   }}1, 
basicstyle=\ttm,
morekeywords={self},              % Add keywords here
keywordstyle=\ttb\color{deepblue},
emph={MyClass,__init__},          % Custom highlighting
emphstyle=\ttb\color{deepred},    % Custom highlighting style
stringstyle=\color{deepgreen},
frame=tb,                         % Any extra options here
showstringspaces=false
}}

\lstdefinestyle{pythonstyling}{
language=Python,
basicstyle=\ttm,
morekeywords={self},              % Add keywords here
keywordstyle=\ttb\color{deepblue},
emph={MyClass,__init__},          % Custom highlighting
emphstyle=\ttb\color{deepred},    % Custom highlighting style
stringstyle=\color{deepgreen},
frame=tb,                         % Any extra options here
showstringspaces=false
}


% Python 
\begin{document}
here some python codes

\begin{lstlisting}[style=pythonstyling]
import numpy as np
class __init__(self, a, b):
    self.a = a
    self.b = b
\end{lstlisting}

\pythonstyle 
\begin{lstlisting}
import numpy as np
class __init__(self, a, b):
    self.a = a
    self.b = b
\end{lstlisting}
\end{document}