Passing credentials into method

clear example of using credentials without having to use environment variables

docs/index.rst

@@ -125,7 +125,10 @@ Authorization Code Flow
 =======================
 To support the **Authorization Code Flow** *Spotipy* provides a
 utility method ``util.prompt_for_user_token`` that will attempt to authorize the
-user.  You can pass your app credentials directly into the method as arguments,
+user.  You can pass your app credentials directly into the method as arguments::
+
+    util.prompt_for_user_token(username,scope,client_id='your-app-redirect-url',client_secret='your-app-redirect-url',redirect_uri='your-app-redirect-url')
+
 or if you are reluctant to immortalize your app credentials in your source code, 
 you can set environment variables like so::