[...]
\begin{document}

\maketitle
\newpage
%\tableofcontents
% \newpage


\appendix
\chapter{Bilag A: Kildekode}
\label{app:source}

\lstset{numbers=left,breaklines=true, language=python, basicstyle=\tiny}

\subsection{SeqCollection.py}
\lstinputlisting{SeqCollection.py}

\section{SeqCollection_test.py}
\lstinputlisting{SeqCollection_test.py}

\end{document}