workaround for lack of "copy" in git

gitCopyFile.py

# Since Git does not have a way to copy files, this implements the workaround from here:
# https://stackoverflow.com/a/46484848/2016290
import argparse
import os
import subprocess

TMP_BRANCH = 'tmpToCopyFile'


def gitCopyFile(origPath, newPath):
    def run(*args):
        print(f'RUNNING {" ".join(args)}')
        subprocess.run(args, shell=True, check=True)
        print()

    # verify that the path exists
    run('git', 'show', origPath)

    # create temp branch
    run('git', 'checkout', '-b', TMP_BRANCH)

    # move file to new name
    run('git', 'mv', origPath, newPath)

    # commit file rename
    commitMsg = input('enter commit message for \'git mv\': ')
    run('git', 'commit', '-m', commitMsg)

    # bring back the original file and commit it
    run('git', 'checkout', 'HEAD~', origPath)
    run('git', 'commit', '-m', 'restore original file')

    # switch back to the previous branch (just like `cd -` in most command line shells)
    run('git', 'checkout', '-')

    # merge the temp branch and delete it
    run('git', 'merge', '--no-ff', TMP_BRANCH)
    run('git', 'branch', '-d', TMP_BRANCH)


if __name__ == '__main__':
    helpstr = 'to workaround git\'s lack of "copy", create a temp branch to rename a file and then merge it back'
    parser = argparse.ArgumentParser(description=helpstr)
    parser.add_argument('origPath')
    parser.add_argument('newPath')
    args = parser.parse_args()

    gitCopyFile(args.origPath, args.newPath)