Provide a dedicated function to return postgresql driver

environ/compat.py

@@ -25,20 +25,21 @@
     class ImproperlyConfigured(Exception):
         pass
 
-# back compatibility with django postgresql package
-if DJANGO_VERSION is not None and DJANGO_VERSION < (2, 0):
-    DJANGO_POSTGRES = 'django.db.backends.postgresql_psycopg2'
-else:
-    # https://docs.djangoproject.com/en/2.0/releases/2.0/#id1
-    DJANGO_POSTGRES = 'django.db.backends.postgresql'
-
 # back compatibility with redis_cache package
 if find_loader('redis_cache'):
     REDIS_DRIVER = 'redis_cache.RedisCache'
 else:
     REDIS_DRIVER = 'django_redis.cache.RedisCache'
 
 
+def choose_postgres_driver():
+    """Backward compatibility for postgresql driver."""
+    old_django = DJANGO_VERSION is not None and DJANGO_VERSION < (2, 0)
+    if old_django:
+        return 'django.db.backends.postgresql_psycopg2'
+    return 'django.db.backends.postgresql'
+
+
 def choose_pymemcache_driver():
     """Backward compatibility for pymemcache."""
     old_django = DJANGO_VERSION is not None and DJANGO_VERSION < (3, 2)
@@ -49,4 +50,8 @@ def choose_pymemcache_driver():
     return 'django.core.cache.backends.memcached.PyMemcacheCache'
 
 
+DJANGO_POSTGRES = choose_postgres_driver()
+"""The name of the PostgreSQL driver."""
+
 PYMEMCACHE_DRIVER = choose_pymemcache_driver()
+"""The name of the Pymemcache driver."""