Add client credentials flow

examples/client_credentials_flow.py

@@ -0,0 +1,10 @@
+from spotipy.oauth2 import SpotifyClientCredentials
+import spotipy
+import pprint
+
+client_credentials_manager = SpotifyClientCredentials()
+sp = spotipy.Spotify(client_credentials_manager=client_credentials_manager)
+
+search_str = 'Muse'
+result = sp.search(search_str)
+pprint.pprint(result)

spotipy/client.py

@@ -40,7 +40,8 @@ class Spotify(object):
 
     trace = False  # Enable tracing?
 
-    def __init__(self, auth=None, requests_session=True):
+    def __init__(self, auth=None, requests_session=True,
+        client_credentials_manager=None):
         '''
         Create a Spotify API object.
 
@@ -50,10 +51,13 @@ class Spotify(object):
             A falsy value disables sessions.
             It should generally be a good idea to keep sessions enabled
             for performance reasons (connection pooling).
+        :param client_credentials_manager:
+            SpotifyClientCredentials object
 
         '''
         self.prefix = 'https://api.spotify.com/v1/'
         self._auth = auth
+        self.client_credentials_manager = client_credentials_manager
 
         if isinstance(requests_session, requests.Session):
             self._session = requests_session
@@ -67,6 +71,9 @@ class Spotify(object):
     def _auth_headers(self):
         if self._auth:
             return {'Authorization': 'Bearer {0}'.format(self._auth)}
+        elif self.client_credentials_manager:
+            token = self.client_credentials_manager.get_access_token()
+            return {'Authorization': 'Bearer {0}'.format(token)}
         else:
             return {}
 

spotipy/oauth2.py

@@ -7,9 +7,76 @@ import json
 import time
 import sys
 
+
 class SpotifyOauthError(Exception):
     pass
 
+
+class SpotifyClientCredentials(object):
+    OAUTH_TOKEN_URL = 'https://accounts.spotify.com/api/token'
+
+    def __init__(self, client_id=None, client_secret=None):
+        """
+        You can either provid a client_id and client_secret to the
+        constructor or set SPOTIPY_CLIENT_ID and SPOTIPY_CLIENT_SECRET
+        environment variables
+        """
+        if not client_id:
+            client_id = os.getenv('SPOTIPY_CLIENT_ID')
+
+        if not client_secret:
+            client_secret = os.getenv('SPOTIPY_CLIENT_SECRET')
+
+        if not client_id:
+            raise SpotifyOauthError('No client id')
+
+        if not client_secret:
+            raise SpotifyOauthError('No client secret')
+
+        self.client_id = client_id
+        self.client_secret = client_secret
+        self.token_info = None
+
+    def get_access_token(self):
+        """
+        If a valid access token is in memory, returns it
+        Else feches a new token and returns it
+        """
+        if self.token_info and not self._is_token_expired(self.token_info):
+            return self.token_info['access_token']
+
+        token_info = self._request_access_token()
+        token_info = self._add_custom_values_to_token_info(token_info)
+        self.token_info = token_info
+        return self.token_info['access_token']
+
+    def _request_access_token(self):
+        """Gets client credentials access token """
+        payload = { 'grant_type': 'client_credentials'}
+
+        auth_header = base64.b64encode(self.client_id + ':' + self.client_secret)
+        headers = {'Authorization': 'Basic %s' % auth_header}
+
+        response = requests.post(self.OAUTH_TOKEN_URL, data=payload,
+            headers=headers, verify=True)
+        if response.status_code is not 200:
+            raise SpotifyOauthError(response.reason)
+        token_info = response.json()
+        return token_info
+
+    def _is_token_expired(self, token_info):
+        now = int(time.time())
+        return token_info['expires_at'] < now
+
+    def _add_custom_values_to_token_info(self, token_info):
+        """
+        Store some values that aren't directly provided by a Web API
+        response.
+        """
+        token_info['expires_at'] = int(time.time()) + token_info['expires_in']
+        return token_info
+
+
 class SpotifyOAuth(object):
     '''
     Implements Authorization Code Flow for Spotify's OAuth implementation.

tests/client_credentials_tests.py

@@ -0,0 +1,27 @@
+# -*- coding: latin-1 -*-
+
+import spotipy
+from  spotipy.oauth2 import SpotifyClientCredentials
+import unittest
+
+'''
+    Client Credentials Requests Tests
+'''
+
+class ClientCredentialsTestSpotipy(unittest.TestCase):
+    '''
+        These tests require user authentication
+    '''
+
+    muse_urn = 'spotify:artist:12Chz98pHFMPJEknJQMWvI'
+
+    def test_request_with_token(self):
+        artist = spotify.artist(self.muse_urn)
+        self.assertTrue(artist['name'] == u'Muse')
+
+
+if __name__ == '__main__':
+    spotify_cc = SpotifyClientCredentials()
+    spotify = spotipy.Spotify(client_credentials_manager=spotify_cc)
+    spotify.trace = False
+    unittest.main()