Refs #28459 -- Improved performance of Model.from_db() when fields are deferred.

2017-08-02 18:16:36 +05:00 · 2017-08-02 18:16:36 +05:00 · 78f7f68021
parent 7bd9639406
commit 78f7f68021
1 changed files with 5 additions and 3 deletions
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@ -489,9 +489,11 @@ class Model(metaclass=ModelBase):
    @classmethod
    def from_db(cls, db, field_names, values):
        if len(values) != len(cls._meta.concrete_fields):
-            values = list(values)
-            values.reverse()
-            values = [values.pop() if f.attname in field_names else DEFERRED for f in cls._meta.concrete_fields]
+            values_iter = iter(values)
+            values = [
+                next(values_iter) if f.attname in field_names else DEFERRED
+                for f in cls._meta.concrete_fields
+            ]
        new = cls(*values)
        new._state.adding = False
        new._state.db = db