format_timezones.py

#!/usr/bin/env python
# coding: utf-8
import sys


def format_timezones(timezones, descriptor=sys.stdout):
    _tz = ()
    for tz in sorted(t.split('/') for t in timezones):
        for indent, region in enumerate(tz):
            if len(_tz) > indent and _tz[indent] == tz[indent]:
                continue
            if len(tz) - 1 == indent:
                descriptor.write('{}- {}\n'.format('  ' * indent, '/'.join(tz)))
            else:
                descriptor.write('{}+ {}\n'.format('  ' * indent, region))
        _tz = tz


if __name__ == '__main__':
    import pytz
    format_timezones(pytz.all_timezones)