#!/usr/bin/python3

import requests

import json

import click

@click.command()

@click.argument('base', nargs=1)

@click.argument('head', nargs=1)

def cli(base, head):

    r = requests.get('https://api.github.com/repos/github/hub/compare/%s...%s' % (base, head))

    data = r.json()

    if not data['status'] == 'ahead':

        raise IOError("Branches are divergent")

    for commit in data['commits']:

        print("- ", commit['commit']['message'].split('\n')[0])

def main():

    cli(obj={})

if __name__ == "__main__":

    main()