Get all non-local tracks from a spotify playlist (#518)

* Create playlist_all_tracks.py

* Update playlist_all_tracks.py

forgot first items from playlist

* print result instead of returning it

* rename to playlist_all_non_local_tracks

* Update playlist_all_non_local_tracks.py

removed "== True" as it's implied
give an example playlist (global top 50)
more comments
corrected typo

* print only length and excluding instead of entire result

examples/playlist_all_non_local_tracks.py

@@ -0,0 +1,30 @@
+# get all non-local tracks of a playlist
+from spotipy.oauth2 import SpotifyClientCredentials
+import spotipy
+
+# playlist id of global top 50
+PlaylistExample = '37i9dQZEVXbMDoHDwVN2tF'
+
+# create spotipy client
+sp = spotipy.Spotify(client_credentials_manager=SpotifyClientCredentials())
+
+# load the first 100 songs
+tracks = []
+result = sp.playlist_tracks(PlaylistExample)
+tracks.extend(result['items'])
+
+# if playlist is larger than 100 songs, continue loading it until end
+while result['next']:
+	result = sp.next(result)
+	tracks.extend(result['items'])
+
+# remove all local songs
+i = 0 # just for counting how many tracks are local
+for item in tracks:
+	if item['is_local']:
+		tracks.remove(item)
+		i += 1
+
+
+# print result
+print("Playlist length: " + str(len(tracks)) + "\nExcluding: " + str(i))