[Zope-Checkins] CVS: Zope/lib/python/Persistence/tests -
test_ExtensionClass.py:1.1.2.1
Jim Fulton
cvs-admin at zope.org
Mon Nov 3 11:20:00 EST 2003
Update of /cvs-repository/Zope/lib/python/Persistence/tests
In directory cvs.zope.org:/tmp/cvs-serv19496/lib/python/Persistence/tests
Added Files:
Tag: zodb33-devel-branch
test_ExtensionClass.py
Log Message:
Added extension to provide a getattr slot that blends the semantics of
persistent.Persistent and ExtensionClass.Base.
=== Added File Zope/lib/python/Persistence/tests/test_ExtensionClass.py ===
##############################################################################
#
# Copyright (c) 2003 Zope Corporation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Test ExtensionClass support in Persistence.Persistent
>>> from ExtensionClass import Base
- Support for a class initialiser:
>>> class C(Persistent):
... def __class_init__(self):
... print 'class init called'
... print self.__name__
... def bar(self):
... return 'bar called'
class init called
C
>>> c = C()
>>> int(c.__class__ is C)
1
>>> int(c.__class__ is type(c))
1
- Provide an inheritedAttribute method for looking up attributes in
base classes:
>>> class C2(C):
... def bar(*a):
... return C2.inheritedAttribute('bar')(*a), 42
class init called
C2
>>> o = C2()
>>> o.bar()
('bar called', 42)
This is for compatability with old code. New code should use super
instead.
The base class, Base, exists mainly to support the __of__ protocol.
The __of__ protocol is similar to __get__ except that __of__ is called
when an implementor is retrieved from an instance as well as from a
class:
>>> class O(Base):
.. def __of__(*a):
.. return a
>>> o1 = O()
>>> o2 = O()
>>> C.o1 = o1
>>> c.o2 = o2
>>> c.o1 == (o1, c)
1
>>> C.o1 == o1
1
>>> int(c.o2 == (o2, c))
1
We accomplish this by making a class that implements __of__ a
descriptor and treating all descriptor ExtensionClasses this way. That
is, if an extension class is a descriptor, it's __get__ method will be
called even when it is retrieved from an instance.
>>> class O(Base):
.. def __get__(*a):
.. return a
..
>>> o1 = O()
>>> o2 = O()
>>> C.o1 = o1
>>> c.o2 = o2
>>> int(c.o1 == (o1, c, type(c)))
1
>>> int(C.o1 == (o1, None, type(c)))
1
>>> int(c.o2 == (o2, c, type(c)))
1
$Id: test_ExtensionClass.py,v 1.1.2.1 2003/11/03 16:20:00 jim Exp $
"""
from Persistence import Persistent
import pickle
def test_mixing():
"""Test working with a classic class
>>> class Classic:
... def x(self):
... return 42
>>> class O(Persistent):
... def __of__(*a):
... return a
>>> class O2(Classic, O):
... def __of__(*a):
... return (O2.inheritedAttribute('__of__')(*a),
... O2.inheritedAttribute('x')(a[0]))
>>> class C(Persistent):
... def __class_init__(self):
... print 'class init called'
... print self.__name__
... def bar(self):
... return 'bar called'
class init called
C
>>> c = C()
>>> o2 = O2()
>>> c.o2 = o2
>>> int(c.o2 == ((o2, c), 42))
1
Test working with a new style
>>> class Modern(object):
... def x(self):
... return 42
>>> class O2(Modern, O):
... def __of__(*a):
... return (O2.inheritedAttribute('__of__')(*a),
... O2.inheritedAttribute('x')(a[0]))
>>> o2 = O2()
>>> c.o2 = o2
>>> int(c.o2 == ((o2, c), 42))
1
"""
def test_class_creation_under_stress():
"""
>>> for i in range(100):
... class B(Persistent):
... print i,
... if i and i%20 == 0:
... print
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
>>> import gc
>>> x = gc.collect()
"""
def proper_error_on_deleattr():
"""
Florent Guillaume wrote:
...
Excellent.
Will it also fix this particularity of ExtensionClass:
>>> class A(Persistent):
... def foo(self):
... self.gee
... def bar(self):
... del self.gee
>>> a=A()
>>> a.foo()
Traceback (most recent call last):
...
AttributeError: gee
>>> a.bar()
Traceback (most recent call last):
...
AttributeError: 'A' object has no attribute 'gee'
I.e., the fact that KeyError is raised whereas a normal class would
raise AttributeError.
"""
def test__basicnew__():
"""
>>> x = Simple.__basicnew__()
>>> x.__dict__
{}
"""
def print_dict(d):
d = d.items()
d.sort()
print '{%s}' % (', '.join(
[('%r: %r' % (k, v)) for (k, v) in d]
))
def cmpattrs(self, other, *attrs):
for attr in attrs:
if attr[:3] in ('_v_', '_p_'):
continue
c = cmp(getattr(self, attr, None), getattr(other, attr, None))
if c:
return c
return 0
class Simple(Persistent):
def __init__(self, name, **kw):
self.__name__ = name
self.__dict__.update(kw)
self._v_favorite_color = 'blue'
self._p_foo = 'bar'
def __cmp__(self, other):
return cmpattrs(self, other, '__class__', *(self.__dict__.keys()))
def test_basic_pickling():
"""
>>> x = Simple('x', aaa=1, bbb='foo')
>>> x.__getnewargs__()
()
>>> print_dict(x.__getstate__())
{'__name__': 'x', 'aaa': 1, 'bbb': 'foo'}
>>> f, (c,), state = x.__reduce__()
>>> f.__name__
'__newobj__'
>>> f.__module__
'copy_reg'
>>> c.__name__
'Simple'
>>> print_dict(state)
{'__name__': 'x', 'aaa': 1, 'bbb': 'foo'}
>>> pickle.loads(pickle.dumps(x)) == x
1
>>> pickle.loads(pickle.dumps(x, 0)) == x
1
>>> pickle.loads(pickle.dumps(x, 1)) == x
1
>>> pickle.loads(pickle.dumps(x, 2)) == x
1
>>> x.__setstate__({'z': 1})
>>> x.__dict__
{'z': 1}
"""
class Custom(Simple):
def __new__(cls, x, y):
r = Persistent.__new__(cls)
r.x, r.y = x, y
return r
def __init__(self, x, y):
self.a = 42
def __getnewargs__(self):
return self.x, self.y
def __getstate__(self):
return self.a
def __setstate__(self, a):
self.a = a
def test_pickling_w_overrides():
"""
>>> x = Custom('x', 'y')
>>> x.a = 99
>>> (f, (c, ax, ay), a) = x.__reduce__()
>>> f.__name__
'__newobj__'
>>> f.__module__
'copy_reg'
>>> c.__name__
'Custom'
>>> ax, ay, a
('x', 'y', 99)
>>> pickle.loads(pickle.dumps(x)) == x
1
>>> pickle.loads(pickle.dumps(x, 0)) == x
1
>>> pickle.loads(pickle.dumps(x, 1)) == x
1
>>> pickle.loads(pickle.dumps(x, 2)) == x
1
"""
class Slotted(Persistent):
__slots__ = 's1', 's2', '_p_splat', '_v_eek'
def __init__(self, s1, s2):
self.s1, self.s2 = s1, s2
self._v_eek = 1
self._p_splat = 2
class SubSlotted(Slotted):
__slots__ = 's3', 's4'
def __init__(self, s1, s2, s3):
Slotted.__init__(self, s1, s2)
self.s3 = s3
def __cmp__(self, other):
return cmpattrs(self, other, '__class__', 's1', 's2', 's3', 's4')
def test_pickling_w_slots_only():
"""
>>> x = SubSlotted('x', 'y', 'z')
>>> x.__getnewargs__()
()
>>> d, s = x.__getstate__()
>>> d
>>> print_dict(s)
{'s1': 'x', 's2': 'y', 's3': 'z'}
>>> pickle.loads(pickle.dumps(x)) == x
1
>>> pickle.loads(pickle.dumps(x, 0)) == x
1
>>> pickle.loads(pickle.dumps(x, 1)) == x
1
>>> pickle.loads(pickle.dumps(x, 2)) == x
1
>>> x.s4 = 'spam'
>>> d, s = x.__getstate__()
>>> d
>>> print_dict(s)
{'s1': 'x', 's2': 'y', 's3': 'z', 's4': 'spam'}
>>> pickle.loads(pickle.dumps(x)) == x
1
>>> pickle.loads(pickle.dumps(x, 0)) == x
1
>>> pickle.loads(pickle.dumps(x, 1)) == x
1
>>> pickle.loads(pickle.dumps(x, 2)) == x
1
"""
class SubSubSlotted(SubSlotted):
def __init__(self, s1, s2, s3, **kw):
SubSlotted.__init__(self, s1, s2, s3)
self.__dict__.update(kw)
self._v_favorite_color = 'blue'
self._p_foo = 'bar'
def __cmp__(self, other):
return cmpattrs(self, other,
'__class__', 's1', 's2', 's3', 's4',
*(self.__dict__.keys()))
def test_pickling_w_slots():
"""
>>> x = SubSubSlotted('x', 'y', 'z', aaa=1, bbb='foo')
>>> x.__getnewargs__()
()
>>> d, s = x.__getstate__()
>>> print_dict(d)
{'aaa': 1, 'bbb': 'foo'}
>>> print_dict(s)
{'s1': 'x', 's2': 'y', 's3': 'z'}
>>> pickle.loads(pickle.dumps(x)) == x
1
>>> pickle.loads(pickle.dumps(x, 0)) == x
1
>>> pickle.loads(pickle.dumps(x, 1)) == x
1
>>> pickle.loads(pickle.dumps(x, 2)) == x
1
>>> x.s4 = 'spam'
>>> d, s = x.__getstate__()
>>> print_dict(d)
{'aaa': 1, 'bbb': 'foo'}
>>> print_dict(s)
{'s1': 'x', 's2': 'y', 's3': 'z', 's4': 'spam'}
>>> pickle.loads(pickle.dumps(x)) == x
1
>>> pickle.loads(pickle.dumps(x, 0)) == x
1
>>> pickle.loads(pickle.dumps(x, 1)) == x
1
>>> pickle.loads(pickle.dumps(x, 2)) == x
1
"""
def test_pickling_w_slots_w_empty_dict():
"""
>>> x = SubSubSlotted('x', 'y', 'z')
>>> x.__getnewargs__()
()
>>> d, s = x.__getstate__()
>>> print_dict(d)
{}
>>> print_dict(s)
{'s1': 'x', 's2': 'y', 's3': 'z'}
>>> pickle.loads(pickle.dumps(x)) == x
1
>>> pickle.loads(pickle.dumps(x, 0)) == x
1
>>> pickle.loads(pickle.dumps(x, 1)) == x
1
>>> pickle.loads(pickle.dumps(x, 2)) == x
1
>>> x.s4 = 'spam'
>>> d, s = x.__getstate__()
>>> print_dict(d)
{}
>>> print_dict(s)
{'s1': 'x', 's2': 'y', 's3': 'z', 's4': 'spam'}
>>> pickle.loads(pickle.dumps(x)) == x
1
>>> pickle.loads(pickle.dumps(x, 0)) == x
1
>>> pickle.loads(pickle.dumps(x, 1)) == x
1
>>> pickle.loads(pickle.dumps(x, 2)) == x
1
"""
def test_setattr_on_extension_type():
"""
>>> for name in 'x', '_x', 'x_', '__x_y__', '___x__', '__x___', '_x_':
... setattr(Persistent, name, 1)
... print getattr(Persistent, name)
... delattr(Persistent, name)
... print getattr(Persistent, name, 0)
1
0
1
0
1
0
1
0
1
0
1
0
1
0
>>> Persistent.__foo__ = 1
Traceback (most recent call last):
...
TypeError: can't set attributes of built-in/extension type """ \
"""'Persistence.Persistent' if the attribute name begins """ \
"""and ends with __ and contains only 4 _ characters
>>> Persistent.__foo__
Traceback (most recent call last):
...
AttributeError: type object 'Persistence.Persistent' """ \
"""has no attribute '__foo__'
>>> del Persistent.__foo__
Traceback (most recent call last):
...
TypeError: can't set attributes of built-in/extension type """ \
"""'Persistence.Persistent' if the attribute name begins """ \
"""and ends with __ and contains only 4 _ characters
"""
from doctest import DocTestSuite
import unittest
def test_suite():
return unittest.TestSuite((
DocTestSuite(),
))
if __name__ == '__main__': unittest.main()
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