Use Parameter defined in PythonTex in Latex to open File

Question

I have a Python code which detects my files. Now I will open it in Latex. But it seems not possible to give the detected names to Latex I have tried this:

\begin{pycode}
l = [f for f in os.listdir('path') if f.endswith('.jpg')]
\end{pycode}
\includegraphics[scale=0.1]{\py{l}}

Because it did not work I have used this:

\newcommand{\filename}{}
\edef\filename{l}

\includegraphics[scale=0.75]{\filename}

I need this because I have different files. They have filename that looks like this: part1_date, part1 is always the same only the date is variable. Therefore the day should be refered in the text (for example like the reference to a equation. And of course it must be printed.

Is it possble to do this with Pythontex? Or can I do this with another method?

Thanks

Answer 1

\py is not expandable. Therefore it cannot directly be used as file name for \includegraphics. But \py can be used to output TeX code that defines a macro. Then the macro contains the string and can be used for \includegraphics.

Example:

\documentclass{article}
\usepackage[a4paper,vmargin=2cm]{geometry}
\usepackage{pythontex}
\usepackage{graphicx}
\usepackage{url}
\usepackage{multido}

\begin{document}
\begin{pycode}
l = [f for f in os.listdir('../') if f.endswith('.jpg')]
\end{pycode}
\py{"\\def\\NumberOfFiles{" + "{}".format(len(l)) + "}"}
\providecommand*{\NumberOfFiles}{0}

\DeclareRobustCommand*{\PrintFile}[1]{%
  \expandafter\PrintFileAux\expandafter{\number#1}%
}
\newcommand*{\PrintFileAux}[1]{%
  \py{"\\path{" + l[#1] + "}"}%
}

\DeclareRobustCommand*{\DefFileName}[1]{%
  \expandafter\DefFileNameAux\expandafter{\number#1}%
}
\newcommand*{\DefFileNameAux}[1]{%
  \py{"\\def\\FileName{" + l[#1] + "}"}%
  \providecommand*{\FileName}{}%
}

\tableofcontents

\section{\NumberOfFiles\ file\ifnum\NumberOfFiles>1 s\fi}

\multido{\i=0+1}{\NumberOfFiles}{%
  \subsection{\PrintFile{\i}}%
  \DefFileName{\i}%
  \ifx\FileName\empty
  \else
    \includegraphics[height=\baselineskip]{\FileName}%
  \fi
}%
\end{document}

Remarks:

• The current directory is .., because python is executed in the auxiliary directory pythontex-files-<jobname> (<jobname> is the name of the main LaTeX file without extension).

• If the path name contains special characters (such as _), then printing needs some more care. It can be printed as verbatim text. The example uses macro \path from package url.

• The loop over all files can be done in different ways. The example implements the loop in LaTeX using \multido of package multido.

  Alternatively the loop can be implemented in Python by calling a LaTeX macro with the file name and/or date as argument.

• The file name could be analyzed at TeX level to extract the date. The more comfortable way would be using Python to extract the date and convert it to the desired format.