From a directory, select all .svg files and turn them into grayscale using Inkscape. Save as .pdf

color_to_grayscale.py

import os
import subprocess

for filename in os.listdir('.'):
  if filename[-3:] == 'svg':
    subprocess.call(["inkscape",
                     "-f",
                     filename,
                     "--verb",
                     "EditSelectAll",
                     "--verb",
                     "org.inkscape.color.desaturate.noprefs",
                     "--verb",
                     "FileSave",
                     "--verb",
                     "FileQuit"])
    subprocess.call(["inkscape",
                    "-f",
                    filename,
                    "--export-pdf=" + filename[:-4] + ".pdf"])