Run autoflake against staged .py files on commit

pre-commit-autoflake.py

#!/usr/bin/python3

"""Runs autoflake on commit. Blocks commit and requests adding changed files
if autoflake fires.

Installation
------------
1. You will need to install autoflake: https://pypi.org/project/autoflake/
     $ pip install --upgrade autoflake
   or
     $ conda install -c auto autoflake
2. Find out where your autoflake has been installed by doing
    $ whereis autoflake
3. Change filename to pre-commit
4. Move to .git/hooks in the top of your git repo
5. Change file permissions
    $ chmod a+x pre-commit
"""


import os
import subprocess
import sys
import tempfile


class bcolors:
    RED = '\033[91m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'


autoflake_loc = '/home/railton/.local/bin/autoflake'

git = subprocess.Popen(
    ['git', 'diff', '--cached', '--name-only', '--diff-filter=AM'],
    stdout=subprocess.PIPE)
staged_files = git.stdout.read().decode("utf-8").strip().splitlines()

# Run autoflake on staged files
updated_files = []
for python_file in [f for f in staged_files if f.endswith('.py')]:
    output = tempfile.NamedTemporaryFile(mode='w')
    autoflake = subprocess.Popen(
        [autoflake_loc, '--remove-all-unused-imports', python_file],
        stdout=output)
    autoflake.communicate()
    if os.stat(output.name).st_size > 0:
        updated_files.append(python_file)

# If autoflake fired, run in-place and abort the commit
if updated_files:
    for python_file in [f for f in staged_files if f.endswith('.py')]:
        autoflake = subprocess.Popen(
            [autoflake_loc, '--in-place', '--remove-all-unused-imports', python_file],
            stdout=subprocess.DEVNULL)
        autoflake.communicate()

    print(bcolors.RED + bcolors.BOLD + ">>> COMMIT ABORTED <<<" + bcolors.ENDC)
    print("Unused imports removed from staged files [{}]".format(
        ', '.join(updated_files)))
    print("Please restage and commit again")
    sys.exit(1)

sys.exit(0)