Delete merged branches in Git

Here is a script I made to delete local and remote branches merged into the current HEAD:

#!/usr/bin/env python3
import subprocess


print('Fetching remote branches...')
subprocess.call('git fetch -p --all', shell=True)

print('Processing remote branches...')

remote_branches = subprocess.check_output(
    'git branch -r origin/* --merged', shell=True).decode().split('\n')

answer = ''
remote_head = ''
for branch in remote_branches:
    branch = branch.strip()
    if branch == remote_head:
        print('Skipping remote branch %r which is the remote head.' % branch)
        continue
    if not branch:
        continue
    remote, branch = branch.split('/', maxsplit=1)
    if not remote_head:
        remote_head = branch.partition('HEAD -> ')[2]
        continue
    if answer != 'A':
        answer = input('Delete remote branch %r? (y/a or Enter) ' % branch).upper()
    if answer in 'YA':
        subprocess.call('git push %s :%s' % (remote, branch), shell=True)

print('Processing local branches...')

local_branches = [branch.strip() for branch in subprocess.check_output(
    'git branch --merged', shell=True).decode().split('\n')]

for branch in local_branches:
    branch = branch.strip()
    if not branch:
        continue
    if branch.startswith('* '):
        print('Skipping current branch')
        continue

    if answer != 'A':
        answer = input('Delete local branch %r? (y/a or Enter) ' % branch).upper()
    if answer in 'YA':
        subprocess.call('git branch -d %s' % branch, shell=True)