alternate 100% python form -- untested.

gistfile1.txt

#!/usr/bin/env python
import os
import sys
import json
import errno
import urllib2
import datetime

from subprocess import call

DEBUG=False

def do_debug(debugString):
    if DEBUG:
        print (debugString)
        
def fetch_repo_list(user):
    try:
        endpoint = "https://api.github.com/users/%s/repos" % user
        apiResults = urllib2.urlopen(endpoint)
        jsonData = apiResults.read()
        repoList=get_repo_from_json(jsonData)
    except Exception as e:
        do_debug("Error in Repo Fetch: %s" % e)
    return repoList

def get_repo_from_json(jsonData):
    repoList=[]
    try:
        data = json.loads(jsonData)
        for repo in data:
            repoDict={'user': repo['owner']['login'], 'name': repo['name'], 'url': repo["git_url"]}
            repoList.append(repoDict)
    except Exception as e:
        do_debug("Error in Json Parse: %s" % e)
    return repoList

def get_bundle_path(sPath,user,now):
    bundlePath="%s/bundles/%s/%s" (sPath, user, now)
    return bundlePath

def get_temp_path(sPath,user):
    tempPath="/tmp/repos/%s/%s" (user, name)
    return tempPath

def mkdir_p(path):
    try:
        os.makedirs(path)
    except OSError as exc:
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else: raise

def rmdir(path):
if os.path.exists(path):
    try:
        os.remove(path)
    except:
        pass

def user_validate(user):
    return user.isalnum()

def usage():
    print "Usage: %s user1 user2 user3 ..." % os.path.basename(__file__)

def main():
    sPath=__file__
    now=datetime.datetime.now().strftime("%Y%m%d-%H%M%S")

    if len(sys.argv[1:]):
        for user in sys.argv[1:]:
            if user_validate(user):
                userRepos=fetch_repo_list(user)
                for repo in userRepos:
                    bundlePath=get_bundle_path(sPath,user,now)
                    tempPath=get_temp_path(user,repo['name'])
                    mkdir_p(bPath)
                    rmdir(tempPath)

                    call(["git clone --mirror %s %s" % (repo['url'], tempPath)])
                    call(["cd %s && git bundle create %s/%s.bundle --all" % (tempPath, bundlePath, repo['name']) ])
    else:
        usage()

if __name__ == "__main__":
main()