find local git branches that do not exist on remote

nonexistingbranches.py

#!/usr/bin/env python

import subprocess

try:
    branches = subprocess.check_output(['git', 'branch', '-a']).splitlines()
except subprocess.CalledProcessError as e:
    quit(e.returncode)


def filter_branches(branches):

    branches = map(lambda l: l[1:].strip() if l.startswith("*") else l.strip(), branches)

    branches = filter(lambda line: "remotes/origin/HEAD ->" not in line, branches)

    return branches


def split_branches(branches):
    local_branches = []
    remote_branches = []

    for b in branches:
        if b.startswith("remotes/origin/"):
            remote_branches.append(b[len("remotes/origin/"):])
        else:
            local_branches.append(b)

    return local_branches, remote_branches


local, remote = split_branches(filter_branches(branches))

missing_branches = [b for b in local if b not in remote]

if len(missing_branches) > 0:
    print("\n".join(missing_branches))
else:
    print("no missing branches")