Problems using listings package

Question

I'm using the listings package to include some source code files in a LaTeX document.

I'm having 2 problems:

1. characters - are not shown in the resulting file
2. characters % are shown overlapped with characters that appear after it.

This is my lstset:

\lstset{
showstringspaces=false,
extendedchars=true,
frameround=fttt,
frame=single,
upquote=true,
breaklines=true
}

And this is how I insert listings:

\begin{figure}[t]
{\small{
\lstinputlisting[language=Python,numbers=left, numberstyle=\tiny]{modProblem.txt}
\caption{\label{fig:modProblem} El problema del operador \%}
}}
\end{figure}

Answer 1

Tried to make you MWE:

\documentclass{article}
\usepackage{listings}
\usepackage{textcomp}

\lstset{
showstringspaces=false,
extendedchars=true,
frameround=fttt,
frame=single,
upquote=true,
breaklines=true
}

\begin{document}
\lstinputlisting[caption=El problema del operador \%  resuelto,language=Python,numbers=left, numberstyle=\small]{primes.py}
\end{document}

It produces normal output (on Windows, using both pdfLaTeX and XeLaTeX on TexWorks):

Only thing that needed to be added was \usepackage{textcomp} in order to use upquote=true,.