delete_unused_files.py

from subprocess import run, DEVNULL
import re

cp = run(['ls', 'graphql'], stdout=PIPE, encoding='utf-8')
for filename in re.split(r'\s+', cp.stdout):
    if filename:
        cp = run(
                'ack -w -r {filename} **/**'.format(filename=filename),
                stdout=DEVNULL,
                shell=True)
        if cp.returncode == 1:
            run(['rm', 'graphql/' + filename])