obtain_token_localhost() use same arguments as prompt_for_user_token()

spotipy/util.py

@@ -150,9 +150,49 @@ def start_local_http_server(port, handler=RequestHandler):
             return server
 
 
-def obtain_token_localhost(username, client_id, client_secret, redirect_uri, cache_path=None, scope=None):
+def obtain_token_localhost(username, scope=None, client_id=None,
+        client_secret=None, redirect_uri=None, cache_path=None):
+
+    ''' prompts the user to login if necessary and returns
+        the user token suitable for use with the spotipy.Spotify 
+        constructor
+
+        Parameters:
+
+         - username - the Spotify username
+         - scope - the desired scope of the request
+         - client_id - the client id of your app
+         - client_secret - the client secret of your app
+         - redirect_uri - the redirect URI of your app
+         - cache_path - path to location to save tokens
+
+    '''
+
     cache_path = cache_path or ".cache-" + username
 
+    if not client_id:
+        client_id = os.getenv('SPOTIPY_CLIENT_ID')
+
+    if not client_secret:
+        client_secret = os.getenv('SPOTIPY_CLIENT_SECRET')
+
+    if not redirect_uri:
+        redirect_uri = os.getenv('SPOTIPY_REDIRECT_URI')
+
+    if not client_id:
+        print('''
+            You need to set your Spotify API credentials. You can do this by
+            setting environment variables like so:
+
+            export SPOTIPY_CLIENT_ID='your-spotify-client-id'
+            export SPOTIPY_CLIENT_SECRET='your-spotify-client-secret'
+            export SPOTIPY_REDIRECT_URI='your-app-redirect-url'
+
+            Get your credentials at     
+                https://developer.spotify.com/my-applications
+        ''')
+        raise spotipy.SpotifyException(550, -1, 'no credentials set')
+
     sp_oauth = oauth2.SpotifyOAuth(client_id, client_secret, redirect_uri, scope=scope, cache_path=cache_path)
 
     token_info = sp_oauth.get_cached_token()