get-gist-fork.py

# -*- coding: utf-8  -*-
"""
Get a github user's fork of a gist.

Given a starting gist id, traverse the forks to find
a gist for the github username provided in the first
parameter of the command line.
"""
import json
import urllib2

base_url = 'https://api.github.com'
base_gist_id = None

def get_fork_list_data(gist_id):
    url = base_url + '/gists/' + gist_id
    if gist_id != base_gist_id:
        url += '/forks'
    rawdata = urllib2.urlopen(url).read()
    jsondata = json.loads(rawdata)
    return jsondata

def fork_list(gist_id):
    origin_gist = get_fork_list_data(gist_id)

    yield origin_gist

    forks = dict([(fork['id'], fork) 
                  for fork in origin_gist['forks']])

    while len(forks):
        for fork_gist_id in forks.keys()[:]:
            fork_list_data = get_fork_list_data(fork_gist_id)
            
            for record in fork_list_data:
                gist_id = record['id']

                yield record

                forks_url = record['forks_url']
                forks[gist_id] = forks_url

            del forks[fork_gist_id]

def find_suitable_gist(gen, username):
    for gist in gen:
        gist_username = gist['owner']['login']
        if gist_username == username:
            gist_git_url = gist['git_pull_url']
            return gist_git_url

def main():
    import sys
    global base_gist_id
    base_gist_id = sys.argv[1]
    github_username = sys.argv[2]

    gist_url = find_suitable_gist( fork_list( base_gist_id ), github_username)
    if gist_url:
        print gist_url

if __name__ == '__main__':
    main()