Change database settings

Edited settings.py to use PostgreSQL. Made some minor changes
in views.py to incorporate the new models.

musicvis/settings.py

@@ -76,8 +76,12 @@ WSGI_APPLICATION = 'musicvis.wsgi.application'
 
 DATABASES = {
     'default': {
-        'ENGINE': 'django.db.backends.sqlite3',
-        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
+        'ENGINE': 'django.db.backends.postgresql_psycopg2',
+        'NAME': 'spotifyvis',
+        'USER': 'django',
+        'PASSWORD': 'django',
+        'HOST': 'localhost',
+        'PORT': '', 
     }
 }
 

requirements.txt

@@ -7,6 +7,7 @@ idna==2.6
 isort==4.3.4
 lazy-object-proxy==1.3.1
 mccabe==0.6.1
+psycopg2==2.7.4
 pylint==1.8.4
 pytz==2018.4
 requests==2.18.4

spotifyvis/models.py

@@ -1,7 +1,7 @@
 from django.db import models
 
-class Artist(models.Model):
 
+class Artist(models.Model):
     class Meta:
         verbose_name = "Artist"
         verbose_name_plural = "Artists"
@@ -16,13 +16,12 @@ class Artist(models.Model):
 
 
 class User(models.Model):
-    
     class Meta:
         verbose_name = "User"
         verbose_name_plural = "Users"
 
-    user_id = models.CharField(primary_key=True, max_length=30)
-    username = models.CharField(max_length=30)
+    user_id = models.CharField(primary_key=True, max_length=30) # the user's Spotify ID
+    username = models.CharField(max_length=30) # User's Spotify user name, if set
 
     def __str__(self):
         return self.username
@@ -65,5 +64,3 @@ class AudioFeatures(models.Model):
 
     def __str__(self):
         return super(AudioFeatures, self).__str__()
-
-

spotifyvis/utils.py

@@ -1,15 +1,17 @@
 import requests
 import math
 import pprint
+from .models import Artist, User, Track, AudioFeatures
 
 #  parse_library {{{ # 
 
-def parse_library(headers, tracks, library_stats):
+def parse_library(headers, tracks, library_stats, user):
     """Scans user's library for certain number of tracks to update library_stats with.
 
     :headers: For API call.
     :tracks: Number of tracks to get from user's library.
     :library_stats: Dictionary containing the data mined from user's library 
+    :user: a User object representing the user whose library we are parsing
 
     :returns: None
 
@@ -20,20 +22,25 @@ def parse_library(headers, tracks, library_stats):
     # keeps track of point to get songs from
     offset = 0
     payload = {'limit': str(limit)}
+    # use two separate variables to track, because the average popularity also requires num_samples 
+    num_samples = 0  # number of actual track samples
+    feature_data_points = 0  # number of feature data analyses (some tracks do not have analyses available)
+
     for _ in range(0, tracks, limit):
         payload['offset'] = str(offset)
         saved_tracks_response = requests.get('https://api.spotify.com/v1/me/tracks', headers=headers, params=payload).json()
-        num_samples = offset
         for track_dict in saved_tracks_response['items']:
-            # Track the number of samples for calculating
-            # audio feature averages and standard deviations on the fly
+            num_samples += 1 
             get_track_info(track_dict['track'], library_stats, num_samples)
             #  get_genre(headers, track_dict['track']['album']['id'])
             audio_features_dict = get_audio_features(headers, track_dict['track']['id'])
             if len(audio_features_dict) != 0:
-                num_samples += 1 
+                # Track the number of audio analyses for calculating
+                # audio feature averages and standard deviations on the fly
+                feature_data_points += 1
+                
                 for feature, feature_data in audio_features_dict.items():
-                    update_audio_feature_stats(feature, feature_data, num_samples, library_stats)
+                    update_audio_feature_stats(feature, feature_data, feature_data_points, library_stats)
             for artist_dict in track_dict['track']['artists']:
                 increase_artist_count(headers, artist_dict['name'], artist_dict['id'], library_stats)
         # calculates num_songs with offset + songs retrieved

spotifyvis/views.py

@@ -9,9 +9,10 @@ import json
 import pprint
 from datetime import datetime
 from .utils import parse_library, process_library_stats
+from .models import User, Track, AudioFeatures, Artist 
 
 TIME_FORMAT = '%Y-%m-%d-%H-%M-%S'
-library_stats = {"audio_features":{}, "genres":{}, "year_released":{}, "artists":{}, "num_songs":0, "popularity":[], "total_runtime":0}
+TRACKS_TO_QUERY = 5
 
 #  generate_random_string {{{ # 
 
@@ -133,12 +134,18 @@ def user_data(request):
     }
 
     user_data_response = requests.get('https://api.spotify.com/v1/me', headers = headers).json()
-    context = {
-        'user_name': user_data_response['display_name'],
-        'id': user_data_response['id'],
-    }
+    request.session['user_id'] = user_data_response['id'] # store the user_id so it may be used to create model
+    request.session['user_name'] = user_data_response['display_name']
+    user = None # will be set to the current user object later
+    try:
+        user = User.objects.get(user_id=request.session['user_id'])
+    except User.DoesNotExist:
+        user = User.objects.create(user_id=request.session['user_id'], user_name=request.session['user_name'])
+    # context = {
+    #     'user_name': user_data_response['display_name'],
+    #     'id': user_data_response['id'],
+    # }
 
-    tracks_to_query = 5
     library_stats = {
         "audio_features":{}, 
         "genres":{}, 
@@ -151,7 +158,7 @@ def user_data(request):
         },   
         "total_runtime": 0
     }
-    parse_library(headers, tracks_to_query, library_stats)
+    parse_library(headers, TRACKS_TO_QUERY, library_stats, user)
     processed_library_stats = process_library_stats(library_stats)
     print("================================================")
     print("Processed data follows\n")