Printing a SymPy LaTeX expression to png e.g. for Markdown or Medium

print_sympy_expr.py

from subprocess import run
import sympy as sp


def print_to_file(fname, expr):
    # See https://tex.stackexchange.com/questions/34054/tex-to-image-over-command-line/34058#34058
    t_start = r"""\documentclass[border=2pt]{standalone}
\usepackage{amsmath}
\usepackage{varwidth}
\begin{document}
\begin{varwidth}{\linewidth}""" 
    t_end = r"""\end{varwidth}
\end{document}"""
    with open(fname, 'w') as f:
        f.write(t_start + '\n')
        f.write(f'\\[ {sp.latex(expr)} \\]\n')
        f.write(t_end + '\n')
    froot = fname.replace('tex', '')
    try:
        run('pdflatex ' + fname, shell=True, check=True)
    except Exception as ex:
        print(f'Error converting {fname} to pdf')
    try:
        run(f'convert -density 300 {froot}pdf -quality 90 -colorspace RGB {froot}png', shell=True, check=True)
    except Exception as ex:
        print('Error converting to png')