Btukfyl

I am using pythontex to read in a large python list from disk into my .tex file; I wish to use the foreach command from the tikz package to do some typesetting for each of the items in the list.

MWE is as follows:

documentclass{article}



usepackage{pythontex}

usepackage{tikz}



begin{document}



begin{pycode}

some_letters = ['A', 'B', 'C']

end{pycode}



normal for-loop:\

foreach letter in {a, b, c} {letter=letter\}



for-loop with texttt{pythontex}:\

foreach letter in {py{some_letters}} {letter=letter\}



end{document}

and is typeset as follows:

    normal for-loop:

letter=a

letter=b

letter=c



    for-loop with pythontex:

letter=['A', 'B', 'C']

The first for-loop displays correctly. The second for-loop is where I attempt to read the python list. py{} returns the python object and what I want are comma separated values like in the first for-loop. I have unsuccessfully tried the following instead of py{some_letters}:

py{*some_letters}  % attempt to explode the python list

py{','.join(some_letters)}  % manually separate with commas

% and defining a generator function to yield one value at a time

Does anyone know how I can use the foreach command with a python iterable? The desired output is as follows:

    normal for-loop:

letter=a

letter=b

letter=c



    for-loop with pythontex:

letter=A

letter=B

letter=C

You can print both things directly in Python, like so:

documentclass{article}



usepackage{pythontex}

usepackage{tikz}



begin{document}



begin{pycode}

import sys

some_letters = ['A', 'B', 'C']

end{pycode}



normal for-loop:\

foreach letter in {a, b, c} {letter=letter\}



for-loop with texttt{pythontex}:\

Version 1:\

py{print("\foreach \letter in {"+','.join(some_letters)+"} {letter=\letter\\}",end='%', flush=True)}

Version 2:\

begin{pycode}

print("\foreach \letter in {"+','.join(some_letters)+"} {letter=\letter\\}")

end{pycode}



end{document}

Caution! As I was struggling to figure out why the py{...} version wasn't working, I realized that you need to have a LaTeX comment (using %) at the end of the line. Apparently, some special character is getting printed out at the end of the line and interpreted as an extra iteration through the loop...ultimately producing None. Make sure to either have % at the end of your print(...) contents OR use the print() option end='%'.