style: address review comments

course_discovery/apps/api/cache.py

@@ -168,4 +168,4 @@ def retrieve(self, request, *args, **kwargs):
         return super().retrieve(request, *args, **kwargs)
 
 def get_utm_source_request_cache_key(partner, user):
-    return get_cache_key(partner=partner.id, user=user.id)
+    return get_cache_key(partner=partner.id, user=user.id)

course_discovery/apps/api/serializers.py

@@ -17,7 +17,6 @@
 from django.utils.text import slugify
 from django.utils.translation import gettext_lazy as _
 from django_countries.serializer_fields import CountryField
-from edx_django_utils.cache import RequestCache, get_cache_key
 from localflavor.us.us_states import CONTIGUOUS_STATES
 from opaque_keys.edx.locator import CourseLocator
 from rest_flex_fields.serializers import FlexFieldsSerializerMixin

course_discovery/apps/api/utils.py

@@ -7,7 +7,7 @@
 from django.core.files.base import ContentFile
 from django.db.models.fields.related import ManyToManyField
 from django.utils.translation import gettext as _
-from edx_django_utils.cache import RequestCache, get_cache_key
+from edx_django_utils.cache import RequestCache
 from opaque_keys.edx.keys import CourseKey
 from requests.exceptions import HTTPError
 from sortedm2m.fields import SortedManyToManyField
@@ -357,16 +357,15 @@ def push_to_studio(self, course_run, create=False, old_course_run_key=None, user
 def use_request_cache(cache_name, key_func):
     def inner(fn):
         @functools.wraps(fn)
-        def foo(*args, **kwargs):
+        def wrapped(*args, **kwargs):
             cache = RequestCache(cache_name)
             cache_key = key_func(*args, **kwargs)
             cached_response = cache.get_cached_response(cache_key)
             if cached_response.is_found:
                 return cached_response.value
-
-            ret_val = fn(*args, **kwargs)
 
+            ret_val = fn(*args, **kwargs)
             cache.set(cache_key, ret_val)
             return ret_val
-        return foo
+        return wrapped
     return inner

course_discovery/apps/api/v1/tests/test_views/test_courses.py

@@ -354,6 +354,11 @@ def test_list(self):
         )
 
     def test_no_repeated_cache_calls_for_utm_calculation(self):
+        """
+        Test that utm source calculation is done only once per request, and not per
+        serialized object on a listing endpoint. Since each utm source calculation
+        requires two cache calls, this reduces the number of calls to the django cache.
+        """
         CourseFactory(
             partner=self.partner, title='Fake Test 1', key='edX+Fake102', type=self.audit_type
         )