Change the default branch of a GH repo. I use it with CodeDeploy in order to deploy different branch each time. Enjoy.

change_default_gh_branch.py

import json,requests,pprint

gh_url 		 = "https://api.github.com"
username 	 = 'wehappyfew'
# a token is needed for 2 Factor Auth, otherwise only Name/Pass
custom_token = 'blablablablablablabla' # a custom personal token from GitHub
repo_name 	 = 'your_repo_name'
new_default_branch = 'something' # this is going to change every time

#encode to JSON
data = json.dumps(
	{
	'name': repo_name,
	'default_branch': new_default_branch
	}
)
# headers = {'Content-Type': 'application/json'} # may need them
# My repo was in an organization, customize the URL for yours accordingly
r = requests.patch(url = '{0}/repos/AN_ORGANIZATION_NAME/{1}'.format(gh_url, repo_name), data=data, auth=(username, custom_token))

print r.status_code
print "Default branch name:",r.json()['default_branch']