texenv 0.0.9

latex inside a python virtual environment

texenv

Create lightweight TeX virtual environments, and use Python methods in 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
Ensure at least the "basic" TeXLive scheme is selected during installation.

texenv requires an existing Python virtual environment, create one with the following command,

python -m venv .venv

Install texenv inside a 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.

Usage

To install packages into the TeX environment,

texenv install <package name>

The package name refers to the TeXLive package name, which is often different than the package name in CTAN. To find the TeXLive package name, search for the package on CTAN and find the "Contained in" section. The package name will be listed next to "TeXLive as".
For example,

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

Or to print to the console:

texenv list

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

texenv sync texrequirements.txt

To compile a .tex file with pdflatex:

texenv run <.tex filepath>

texenv provides a preprocessor that can be used to call Python methods directly from TeX code. This is useful for generating figures and tables in python, or writing complicated macros that are difficult in LaTeX. The example below shows a simple use case:

Contents of example.tex:

\documentclass{article}

% required package for inserting figures
\usepackage{graphicx}

% 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)

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.

texenv run example.tex

Full example: examples/macro_example/macro_example.tex

Slideshows

texenv provides a simple way to generate PDF slideshow presentations directly from Python. Matplotlib figures, images, and LaTeX code 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. The following settings in settings.json should configure texenv to run on .tex files when they are saved. Note that this feature only works when VSCode is opened as a workspace.

    "[latex]": {
        "editor.formatOnSave": false,
    },
    "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%",
            "VIRTUAL_ENV": "%WORKSPACE_FOLDER%/.venv"
        }
        }
    ],
    "latex-workshop.view.pdf.internal.synctex.keybinding": "double-click",
    "latex-workshop.latex.autoBuild.run": "onSave",

Troubleshooting

texenv installs lightweight version of LaTeX into the virtual environment (equivalent to the "basic" TeXLive distribution). Most packages and fonts will need to be installed after the environment is initialized. A couple of useful TeXLive packages that will solve a lot of missing package errors:

texenv install collection-latexrecommended
texenv install collection-fontsrecommended

texenv includes a parser for the rather verbose pdflatex log files, and attempts to show only the relevant error messages. For example,

RuntimeError: pdfTEX Error on line: 9. LaTeX Error: File `hyphenat.sty' not found.
Emergency stop.

A link to the full log file is also included below the error message.

License

texenv is licensed under the MIT License.