Replaced unnecessary str()/bytes() calls with literals.

django/db/backends/base/schema.py

@@ -282,9 +282,9 @@ class BaseDatabaseSchemaEditor:
             default = field.get_default()
         elif not field.null and field.blank and field.empty_strings_allowed:
             if field.get_internal_type() == "BinaryField":
-                default = bytes()
+                default = b''
             else:
-                default = str()
+                default = ''
         elif getattr(field, 'auto_now', False) or getattr(field, 'auto_now_add', False):
             default = datetime.now()
             internal_type = field.get_internal_type()

tests/servers/tests.py

@@ -250,7 +250,7 @@ class LiveServerPort(LiveServerBase):
 
     def test_specified_port_bind(self):
         """LiveServerTestCase.port customizes the server's port."""
-        TestCase = type(str('TestCase'), (LiveServerBase,), {})
+        TestCase = type('TestCase', (LiveServerBase,), {})
         # Find an open port and tell TestCase to use it.
         s = socket.socket()
         s.bind(('', 0))