Refactor saving History obj

From import_history and parse_history. Also refactor getting CSV
information from import_history.

api/utils.py

@@ -236,12 +236,14 @@ def get_artists_in_genre(user, genre, max_songs):
 
 #  }}} get_artists_in_genre # 
 
+#  save_track_artists {{{ # 
+
 def save_track_artists(track_dict, artist_genre_queue, user_headers):
     """ Update artist info before creating Track so that Track object can
     reference Artist object.
 
-    :track_dict: TODO
-    :returns: None
+    :track_dict: response from Spotify API for track
+    :returns: list of Artist objects in Track
 
     """
     track_artists = []
@@ -259,6 +261,10 @@ def save_track_artists(track_dict, artist_genre_queue, user_headers):
 
     return track_artists
 
+#  }}} save_track_artists # 
+
+#  get_user_header {{{ # 
+
 def get_user_header(user_obj):
     """Returns the authorization string needed to make an API call.
 
@@ -284,3 +290,44 @@ def get_user_header(user_obj):
         user_obj.save()
 
     return {'Authorization': "Bearer " + user_obj.access_token}
+
+#  }}}  get_user_header # 
+
+def save_history_obj (user, timestamp, track):
+    """Return (get/create) a History object with the specified parameters. Can't
+    use built-in get_or_create since don't know auto PK.
+
+    :user: User object History should be associated with
+    :timestamp: time at which song was listened to
+    :track: Track object for song
+    :returns: History object
+
+    """
+    history_query = History.objects.filter(user__exact=user,
+            timestamp__exact=timestamp)
+    if len(history_query) == 0:
+        history_obj = History.objects.create(user=user, timestamp=timestamp,
+                track=track)
+    else:
+        history_obj = history_query[0]
+
+    return history_obj
+
+def get_next_history_row(csv_reader, headers, prev_info):
+    """Return formatted information from next row in history CSV file.
+
+    :csv_reader: TODO
+    :headers: 
+    :prev_info: history_obj_info of last row in case no more rows
+    :returns: (boolean of if last row, dict with information of next row) 
+
+    """
+    try:
+        row = next(csv_reader)
+        #  if Track.objects.filter(id__exact=row[1]).exists():
+        history_obj_info = {}
+        for i in range(len(headers)):
+            history_obj_info[headers[i]] = row[i]
+        return False, history_obj_info
+    except StopIteration:
+        return True, prev_info

api/views.py

@@ -150,10 +150,8 @@ def parse_history(request, user_secret):
                 user_headers)
         track_obj, track_created = save_track_obj(track_dict['track'],
                 track_artists, None) 
-        history_obj, history_created = History.objects.get_or_create(
-                user=user_obj,
-                timestamp=parse(track_dict['played_at']),
-                track=track_obj,)
+        history_obj = save_history_obj(user_obj, parse(track_dict['played_at']),
+                track_obj)
 
         if console_logging:
             tracks_processed += 1
@@ -257,19 +255,12 @@ def import_history(request, upload_id):
         history_obj_info_lst = []
         artist_genre_queue = []
 
-        next(csv_reader)
-        row = next(csv_reader)
-        last_row = False
+        # skip header row
+        last_row, history_obj_info = get_next_history_row(csv_reader, headers,
+                {})
         while not last_row:
-    
-            #  if Track.objects.filter(id__exact=row[1]).exists():
-            history_obj_info = {}
-            for i in range(len(headers)):
-                history_obj_info[headers[i]] = row[i]
-            try:
-                row = next(csv_reader)
-            except StopIteration:
-                last_row = True
+            last_row, history_obj_info = get_next_history_row(csv_reader,
+                    headers, history_obj_info)
 
     #  }}} setup # 
 
@@ -290,33 +281,22 @@ def import_history(request, upload_id):
                 #  }}} get tracks_response # 
 
                 for track_dict in tracks_response:
-                    #  create History obj {{{ # 
-                    
                     # don't associate history track with User, not necessarily in their
                     # library
                     track_artists = save_track_artists(track_dict, artist_genre_queue,
                             user_headers)
-                    track_obj, track_created = save_track_obj(track_dict, track_artists, None)
+                    track_obj, track_created = save_track_obj(track_dict,
+                            track_artists, None)
 
-                    timestamp = parse(history_obj_info_lst[responses_processed]['timestamp'])
-                    # missing PK to do get_or_create
-                    history_query = \
-                        History.objects.filter(user__exact=upload_obj.user,
-                                timestamp__exact=timestamp)
-                    if len(history_query) == 0:
-                        history_obj = \
-                            History.objects.create(user=upload_obj.user,
-                                    timestamp=timestamp, 
-                                    track=track_obj,)
-                    else:
-                        history_obj = history_query[0]
+                    timestamp = \
+                        parse(history_obj_info_lst[responses_processed]['timestamp'])
+                    history_obj = save_history_obj(upload_obj.user, timestamp,
+                            track_obj)
 
                     if console_logging:
                         print("Processed row #{}: {}".format(
                             (rows_read - TRACKS_LIMIT) + responses_processed, history_obj,))
                         responses_processed += 1
-                    
-                    #  }}} create History obj # 
 
                 history_obj_info_lst = []