python url shortener with goo.gl

surl.py

#!/usr/bin/env python
# Get a Google API from here:
# https://console.developers.google.com/projectselector/apis/credentials?pli=1

import argparse
import json
import requests

GOOGLE_URL_SHORTEN_API = ''

parser = argparse.ArgumentParser(description='Shorten URL with goo.gl')
parser.add_argument('url', metavar='url', help='URL to be shortened')


def google_url_shorten(url):
    req_url = 'https://www.googleapis.com/urlshortener/v1/url?key=' + GOOGLE_URL_SHORTEN_API
    payload = {'longUrl': url}
    headers = {'content-type': 'application/json'}
    r = requests.post(req_url, data=json.dumps(payload), headers=headers)
    resp = json.loads(r.text)
    return resp['id']

args = parser.parse_args()
print(google_url_shorten(args.url))