Send a message to a user on Last.fm using Goa credentials

lastfm-shout.py

from gi.repository import Goa
from md5 import md5
import sys
import requests

if len(sys.argv) < 3:
    print "Usage: %s USER [MESSAGE]" % sys.argv[0]
    sys.exit()

user = sys.argv[1]
message = sys.argv[2]

client = Goa.Client.new_sync(None)
accounts = client.get_accounts()

for obj in accounts:
    account = obj.get_account()
    if account.props.provider_name == "Last.fm":
        oauth2 = obj.get_oauth2_based()
        break

if oauth2 is None:
    sys.exit()

api_key = oauth2.props.client_id
sk = oauth2.call_get_access_token_sync(None)[0]
secret = oauth2.props.client_secret

sig = ("api_key%smessage%smethoduser.shoutsk%suser%s%s" %
            (api_key, message, sk, user, secret))

api_sig = md5(sig).hexdigest()

r = requests.post("https://ws.audioscrobbler.com/2.0/", {
                    "api_key": api_key,
                    "method": "user.shout",
                    "message": message,
                    "user": user,
                    "sk": sk,
                    "api_sig": api_sig})

print r.status_code, r.reason
print r.text