Convert Latex Equations to PNG (For Medium posts)

convert_equation.py

import os
import subprocess
import argparse
import shlex

FIXED = r"""\documentclass{standalone}
\usepackage{xcolor}
\usepackage{amsmath}
\usepackage[utf8]{inputenc}
\usepackage[charter]{mathdesign}
\begin{document}
\begin{minipage}{178pt}
\begin{align*}
  REPLACEME
\end{align*}
\end{minipage}
\end{document}"""

CMD = r"""convert -density 1200 temp_equation.pdf 
  -resize 1400 
  -gravity South -background white -splice 0x1 
    -background black -splice 0x1 
    -trim  +repage -chop 0x1 
  -gravity North -background white -splice 0x1 
    -background black -splice 0x1 
    -trim  +repage -chop 0x1 
  REPLACEME"""

if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('equation')
    parser.add_argument('name')
    args = parser.parse_args()

    print("~ Equation: {}".format(args.equation))

    out = FIXED.replace("REPLACEME", args.equation)
    with open('temp_equation.tex','w') as f:
      f.write(out)

    cmd = ['pdflatex', '-interaction', 'nonstopmode', 'temp_equation.tex']
    proc = subprocess.Popen(cmd)
    proc.communicate()

    retcode = proc.returncode
    if not retcode == 0:
        os.unlink('temp_equation.pdf')
        raise ValueError('Error {} executing command: {}'.format(retcode, ' '.join(cmd))) 

    os.unlink('temp_equation.tex')
    os.unlink('temp_equation.log')
    os.unlink('temp_equation.aux')

    magick_cmd = CMD.replace("REPLACEME", args.name)
    cmd = shlex.split('{}'.format(magick_cmd))
    print(cmd)
    proc = subprocess.Popen(cmd)
    proc.communicate()

    retcode = proc.returncode
    if not retcode == 0:
        os.unlink(args.name)
        raise ValueError('Error {} executing command: {}'.format(retcode, ' '.join(magick_cmd))) 

    os.unlink('temp_equation.pdf')