texenv 0.0.8

latex inside a python virtual environment

texenv

Create lightweight TeX virtual environments, and use Python methods directly from TeX code.

Installation

texenv is currently only supported on Windows, and requires texlive to be installed on the system.
https://tug.org/texlive/windows.html#install

Install texenv inside an existing Python virtual environment,

pip install texenv

To create a standalone TeX installation visible only to the current environment,

texenv init

This installs a bare-bones version of LaTeX in .venv/tex and modifies the environment activation scripts so this TeX installation is used instead of the base installation. The console needs to be closed and re-opened for the changes to take effect.

Usage

The TeX environment supports the standard tlmgr tool which can be used to install and update packages as normal.

tlmgr install <package name>

To write all currently installed TeX packages in the environment to a file (excluding core packages required for LaTeX to run),

texenv freeze > texrequirements.txt

To synchronize the TeX installation with the packages found in a requirements file,

texenv sync texrequirements.txt

.tex files can be compiled in the environment using the standard tools (i.e pdflatex). texenv also supports a preprocessor that can be used to call Python methods directly from TeX code. This is useful for generating figures and table data from python, or doing math that is difficult in LaTeX code. The example below shows a simple use case:

Contents of example.tex:

\documentclass{article}

% import a python module either installed in the environment, or just a file in the same folder as the .tex file.
% In this case figures.py is in the same folder.
\import\figures

% preprocessor variables can be defined with \pydef followed by the variable name and value.
\pydef\cleanfig true

\begin{document}
  
  % call a python method. Supports arguments and kwargs, but all are passed in as string types. The return type of 
  % the method must be a string as it is inserted directly into the TeX code.
  \figures\figA[clean=\cleanfig, width=5in]
   
\end{document}

Contents of figures.py, located in the same directory as example.tex:

from texenv.macros import figure
import matplotlib.pyplot as plt

def figA(clean="true", width="3in", **kwargs):
    
    if clean == "false":
        return figure(file="figA.pdf", width=width, **kwargs)

    fig, ax1 = plt.subplots(1, 1)
    ax1.plot(range(11, 17))

    fig.savefig("figA.pdf")

    return figure(file="figA.pdf", width=width, **kwargs)

Compile on command line inside virtual environment:

texenv run example.tex

Full example: examples/macro_example/macro_example.tex

The run command invokes the preprocessor, and then calls pdflatex on the post-processed .tex file. The synctex file is modified after running pdflatex so the intermediate file is transparent to synctex.

Slideshows

texenv provides a simple way to generate PDF slideshow presentations directly from Python. Matplotlib figures, images, and LaTeX code (as strings in Python) can be assembled together into a slide using the Presentation class:

from texenv import Presentation, datatable

... 

# text to place on slide. This is interpreted as an enumerate list if \item appears first in the string.
# Otherwise, the text is inserted directly as LaTeX code and supports math macros etc...
text = r"""
\item Bullet 1
\item Bullet 2
\[ \nabla \times \mathbf{E} = -\mu {\partial \mathbf{H} \over \partial t} \]
\[ \nabla \times \mathbf{H} = \varepsilon {\partial \mathbf{E} \over \partial t} \]
"""

# create a table with header names, and a format string applied to each cell
table = datatable(
    np.arange(16).reshape((4, 4)), header_row=[f"Header {i}" for i in range(4)], formatter="{:.2f}"
)

pres = Presentation("example_slides.pdf")

# add the content to the first slide. The layout will be a 2x2 grid, with the figure centered along both rows in the
# second column. The text and table will split the first column. 
pres.add_slide(
    content=[[text, fig], 
             [table, None]], 
    title="Example TeX Slides", 
    width_ratio=(1, 2) # make the second column twice as wide as the first column.
)

pres.save()

Full example: examples/slideshow/slideshow.py

VSCode Setup

texenv is designed to work with the Latex Workshop extension in VSCode. Once the extension is installed, the following settings should be added to the user settings.json file:

    "latex-workshop.latex.recipes": [
        {
            "name": "texenv",
            "tools": [
                "texenv"
            ]
        }
    ],
    "latex-workshop.latex.tools": [
        {
          "name": "texenv",
          "command": "texenv",
          "args": [
            "run", "%DOC_EXT%"
          ],
          "env": {
            "Path": "%WORKSPACE_FOLDER%/.venv/tex/bin/windows;%WORKSPACE_FOLDER%/.venv/Scripts;%PATH%"
          }
        },
    ],
    "latex-workshop.view.pdf.internal.synctex.keybinding": "double-click",
    "latex-workshop.latex.autoBuild.run": "onSave",

License

texenv is licensed under the MIT License.