# Can one customize lstlisting environment?

I want to add some Python source code to my LaTeX document, but I want to apply some customization. Currently, I have something like this:

\documentclass{article}
\usepackage[utf8]{inputenc}

\usepackage{listings}
\usepackage{color}

\definecolor{codegreen}{rgb}{0,0.6,0}
\definecolor{codegray}{rgb}{0.5,0.5,0.5}
\definecolor{codepurple}{rgb}{0.58,0,0.82}
\definecolor{backcolour}{rgb}{0.95,0.95,0.92}

\lstdefinestyle{mystyle}{
backgroundcolor=\color{backcolour},
keywordstyle=\color{magenta},
numberstyle=\tiny\color{codegray},
stringstyle=\color{codepurple},
basicstyle=\footnotesize,
breakatwhitespace=false,
breaklines=true,
captionpos=b,
keepspaces=true,
numbers=left,
numbersep=5pt,
showspaces=false,
showstringspaces=false,
showtabs=false,
tabsize=2
}

\lstset{style=mystyle}

\begin{document}

\begin{lstlisting}[language=Python, caption=Python example]
# Importing the sys package
import sys

def testfunc(a):
return a + a

print "Testing:", str(testfunc(3))
\end{lstlisting}

\end{document}


The point is that above customization that I have works to some extend, but I want to further customize it in two ways. First, I want to apply a specific color to all the numbers in the source code. For example, in the above example, the number 3 inside str(testfunc(3)) should have a specific color that I set (let's say blue). So I simply want all the numbers to have a custom color that I set. Second, I want certain keywords of my choice to have another color (let's say yellow). For example, I want the testfunc, print and str keywords to be yellow. So can one add these type of customization in lstlisting environment? If yes, how?

The following code does the trick for the three keywords; as far as I can remember, the listings package makes no provision for coloring the numbers in the code.

\documentclass[a4paper]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

\usepackage{listings}
\usepackage{color}

\definecolor{codegreen}{rgb}{0,0.6,0}
\definecolor{codegray}{rgb}{0.5,0.5,0.5}
\definecolor{codepurple}{rgb}{0.58,0,0.82}
\definecolor{codeyellow}{rgb}{0.67,0.67,0.0}
\definecolor{backcolour}{rgb}{0.95,0.95,0.92}

\lstdefinestyle{mystyle}{
language=Python,
backgroundcolor=\color{backcolour},
keywordstyle=\color{magenta},
emph={testfunc,print,src},
emphstyle=\color{codeyellow},
numberstyle=\tiny\color{codegray},
stringstyle=\color{codepurple},
basicstyle=\footnotesize,
breakatwhitespace=false,
breaklines=true,
captionpos=b,
keepspaces=true,
numbers=left,
numbersep=5pt,
showspaces=false,
showstringspaces=false,
showtabs=false,
tabsize=2
}

\lstset{style=mystyle}

\begin{document}

\begin{lstlisting}[style=mystyle, caption=Python example]
# Importing the sys package
import sys

def testfunc(a):
return a + a

print "Testing:", str(testfunc(3))
\end{lstlisting}

\end{document}

• Way cleaner solution than mine. +1 – gebruiker Mar 30 '18 at 12:12
• For the numbers you can probably make all numerals keywords... – gebruiker Mar 30 '18 at 12:13
• @gebruiker: I think it is much cleaner with emph/emphstyle. – GuM Mar 30 '18 at 12:16

I got the result you want by using the literate-key (manual section 6.4).

literate=   {0}{{{\color{blue}0}}}1
{1}{{{\color{blue}1}}}1
{2}{{{\color{blue}2}}}1
{3}{{{\color{blue}3}}}1
{4}{{{\color{blue}4}}}1
{5}{{{\color{blue}5}}}1
{6}{{{\color{blue}6}}}1
{7}{{{\color{blue}7}}}1
{8}{{{\color{blue}8}}}1
{9}{{{\color{blue}9}}}1
{testfunc}{{{\color{yellow}testfunc}}}8


Add this to mystyle and you're good to go.

(I can't explain why you would need so many curly braces)

N.B. I cannot think of a way to make decimal points blue as well, whilst leaving normal period alone. As it is, only numerals are affected.

• Right! (+1). For the number of braces, you could omit the pair around the “find text” (e.g., 3{{{\color{codeblue}3}}}1), but I’d agree with you that the “replacement text” apparently needs one pair more than what would seem logical. Keep in mind, however, that TeX sometimes strips a pair of braces off a macro argument. – GuM Mar 30 '18 at 12:30
• One of us must resolve to include the other’s answer into their own, so that a complete answer is made. Since you have fewer rep points than I have, I think it is fair to let you do so. (:-) – GuM Mar 30 '18 at 12:39
• I would say we just gave two different ways to solve the problem. I don't fell there's a need to merge. Both answers can hold their own. (I appreciate you would let my answer be the main one, but I pay very little attention to my rep points.) – gebruiker Mar 30 '18 at 12:46
• @gebruiker This is quite interesting and seems to work, but the problem is that if let's say variable name contains a number like var1 then, the 1 there is also with a different color. Whereas I need just regular numbers, or more precisely lone numbers, not part of any other text. Also for a text, something like testfunc it seems to leave blank space before and after it. – pixel Mar 30 '18 at 15:05