Merge lp:~cjwatson/storm/py3-metaclass into lp:storm

[Colin Watson]

Use six.with_metaclass to support Python 3's metaclass syntax.

[Kristian Glass (doismellburning)]

For what it's worth, this definitely looks plausible and reasonable to me, but I'm not currently familiar enough with metaclasses, metaclass changes between 2/3, and/or Storm's usage thereof, to necessarily give a _positive_ review

[Simon Poirier (simpoir)]

+1 exactly what I'd expect.

review: Approve

=== modified file 'storm/base.py'
--- storm/base.py	2019-06-05 11:41:07 +0000
+++ storm/base.py	2019-08-11 09:00:12 +0000
@@ -20,18 +20,19 @@
 #
 from __future__ import print_function
 
+import six
+
 from storm.properties import PropertyPublisherMeta
 
 
 __all__ = ["Storm"]
 
 
-class Storm(object):
+class Storm(six.with_metaclass(PropertyPublisherMeta, object)):
     """An optional base class for objects stored in a Storm Store.
 
     It causes your subclasses to be associated with a Storm
     PropertyRegistry. It is necessary to use this if you want to
     specify References with strings.
     """
-    __metaclass__ = PropertyPublisherMeta
 
 
=== modified file 'storm/sqlobject.py'
--- storm/sqlobject.py	2019-06-05 11:41:07 +0000
+++ storm/sqlobject.py	2019-08-11 09:00:12 +0000
@@ -28,6 +28,8 @@
 import re
 import warnings
 
+import six
+
 from storm.properties import (
     RawStr, Int, Bool, Float, DateTime, Date, TimeDelta)
 from storm.references import Reference, ReferenceSet
@@ -261,7 +263,7 @@
             return getattr(self._cls, attr)
 
 
-class SQLObjectBase(Storm):
+class SQLObjectBase(six.with_metaclass(SQLObjectMeta, Storm)):
     """The root class of all SQLObject-emulating classes in your application.
 
     The general strategy for using Storm's SQLObject emulation layer
@@ -271,7 +273,6 @@
     even be implemented as returning a global L{Store} instance. Then
     all database classes should subclass that class.
     """
-    __metaclass__ = SQLObjectMeta
 
     q = DotQ()
     _SO_creating = False
 
=== modified file 'tests/info.py'
--- tests/info.py	2019-06-05 11:41:07 +0000
+++ tests/info.py	2019-08-11 09:00:12 +0000
@@ -23,6 +23,8 @@
 from weakref import ref
 import gc
 
+import six
+
 from storm.exceptions import ClassInfoError
 from storm.properties import Property
 from storm.variables import Variable
@@ -571,8 +573,7 @@
                 cls = type.__new__(meta_cls, name, bases, dict)
                 cls.__storm_table__ = "HAH! GOTCH YA!"
                 return cls
-        class Class(object):
-            __metaclass__ = MetaClass
+        class Class(six.with_metaclass(MetaClass, object)):
             __storm_table__ = "table"
             prop1 = Property("column1", primary=True)
         Alias = ClassAlias(Class, "USE_THIS")
 
=== modified file 'tests/mocker.py'
--- tests/mocker.py	2019-06-07 17:14:33 +0000
+++ tests/mocker.py	2019-08-11 09:00:12 +0000
@@ -13,6 +13,7 @@
 import os
 import gc
 
+import six
 from six.moves import builtins
 
 
@@ -324,7 +325,14 @@
         return bound_method
 
 
-class MockerBase(object):
+class MockerMeta(type):
+
+    def __init__(self, name, bases, dict):
+        # Make independent lists on each subclass, inheriting from parent.
+        self._recorders = list(getattr(self, "_recorders", ()))
+
+
+class MockerBase(six.with_metaclass(MockerMeta, object)):
     """Controller of mock objects.
 
     A mocker instance is used to command recording and replay of
@@ -380,11 +388,6 @@
     # For convenience only.
     on = expect
 
-    class __metaclass__(type):
-        def __init__(self, name, bases, dict):
-            # Make independent lists on each subclass, inheriting from parent.
-            self._recorders = list(getattr(self, "_recorders", ()))
-
     def __init__(self):
         self._recorders = self._recorders[:]
         self._events = []
 
=== modified file 'tests/properties.py'
--- tests/properties.py	2019-06-05 11:41:07 +0000
+++ tests/properties.py	2019-08-11 09:00:12 +0000
@@ -25,6 +25,8 @@
 import gc
 import uuid
 
+import six
+
 from storm.compat import json
 from storm.exceptions import NoneError, PropertyPathError
 from storm.properties import PropertyPublisherMeta
@@ -986,8 +988,8 @@
     def setUp(self):
         TestHelper.setUp(self)
 
-        class Base(object):
-            __metaclass__ = PropertyPublisherMeta
+        class Base(six.with_metaclass(PropertyPublisherMeta, object)):
+            pass
 
         class Class(Base):
             __storm_table__ = "mytable"
 
=== modified file 'tests/store/base.py'
--- tests/store/base.py	2019-06-07 17:14:33 +0000
+++ tests/store/base.py	2019-08-11 09:00:12 +0000
@@ -4454,8 +4454,8 @@
         self.assertRaises(NoStoreError, foo2.bars.remove, object())
 
     def test_string_reference(self):
-        class Base(object):
-            __metaclass__ = PropertyPublisherMeta
+        class Base(six.with_metaclass(PropertyPublisherMeta, object)):
+            pass
 
         class MyBar(Base):
             __storm_table__ = "bar"
@@ -4481,8 +4481,8 @@
         metaclass.  This makes it possible to work around problems with
         circular dependencies by delaying property resolution.
         """
-        class Base(object):
-            __metaclass__ = PropertyPublisherMeta
+        class Base(six.with_metaclass(PropertyPublisherMeta, object)):
+            pass
 
         class MyFoo(Base):
             __storm_table__ = "foo"
@@ -4521,8 +4521,8 @@
         metaclass.  This makes it possible to work around problems with
         circular dependencies by delaying resolution of the order by column.
         """
-        class Base(object):
-            __metaclass__ = PropertyPublisherMeta
+        class Base(six.with_metaclass(PropertyPublisherMeta, object)):
+            pass
 
         class MyFoo(Base):
             __storm_table__ = "foo"
@@ -5766,8 +5766,8 @@
         self.assertEquals(foo.title, "New Title")
 
     def get_bar_proxy_with_string(self):
-        class Base(object):
-            __metaclass__ = PropertyPublisherMeta
+        class Base(six.with_metaclass(PropertyPublisherMeta, object)):
+            pass
 
         class MyBarProxy(Base):
             __storm_table__ = "bar"