def test_unintialized_modules(self):
# Testing uninitialized module objects...
from types import ModuleType as M
m = M.__new__(M)
str(m)
self.assertEqual(hasattr(m, "__name__"), 0)
self.assertEqual(hasattr(m, "__file__"), 0)
self.assertEqual(hasattr(m, "foo"), 0)
self.assertFalse(m.__dict__) # None or {} are both reasonable answers
m.foo = 1
self.assertEqual(m.__dict__, {"foo": 1})
python类__new__()的实例源码
def test_complexes(self):
# Testing complex operations...
self.number_operators(100.0j, 3.0j, skip=['lt', 'le', 'gt', 'ge',
'int', 'float',
'divmod', 'mod'])
class Number(complex):
__slots__ = ['prec']
def __new__(cls, *args, **kwds):
result = complex.__new__(cls, *args)
result.prec = kwds.get('prec', 12)
return result
def __repr__(self):
prec = self.prec
if self.imag == 0.0:
return "%.*g" % (prec, self.real)
if self.real == 0.0:
return "%.*gj" % (prec, self.imag)
return "(%.*g+%.*gj)" % (prec, self.real, prec, self.imag)
__str__ = __repr__
a = Number(3.14, prec=6)
self.assertEqual(repr(a), "3.14")
self.assertEqual(a.prec, 6)
a = Number(a, prec=2)
self.assertEqual(repr(a), "3.1")
self.assertEqual(a.prec, 2)
a = Number(234.5)
self.assertEqual(repr(a), "234.5")
self.assertEqual(a.prec, 12)
def test_unintialized_modules(self):
# Testing uninitialized module objects...
from types import ModuleType as M
m = M.__new__(M)
str(m)
self.assertNotHasAttr(m, "__name__")
self.assertNotHasAttr(m, "__file__")
self.assertNotHasAttr(m, "foo")
self.assertFalse(m.__dict__) # None or {} are both reasonable answers
m.foo = 1
self.assertEqual(m.__dict__, {"foo": 1})
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
class WorkOnce(type):
def __new__(self, name, bases, ns):
self.flag = 0
return super(WorkOnce, self).__new__(WorkOnce, name, bases, ns)
def mro(self):
if self.flag > 0:
raise RuntimeError("bozo")
else:
self.flag += 1
return type.mro(self)
class WorkAlways(type):
def mro(self):
# this is here to make sure that .mro()s aren't called
# with an exception set (which was possible at one point).
# An error message will be printed in a debug build.
# What's a good way to test for this?
return type.mro(self)
class C(object):
pass
class C2(object):
pass
class D(C):
pass
class E(D):
pass
class F(D, metaclass=WorkOnce):
pass
class G(D, metaclass=WorkAlways):
pass
# Immediate subclasses have their mro's adjusted in alphabetical
# order, so E's will get adjusted before adjusting F's fails. We
# check here that E's gets restored.
E_mro_before = E.__mro__
D_mro_before = D.__mro__
try:
D.__bases__ = (C2,)
except RuntimeError:
self.assertEqual(E.__mro__, E_mro_before)
self.assertEqual(D.__mro__, D_mro_before)
else:
self.fail("exception not propagated")
def test_altmro(self):
# Testing mro() and overriding it...
class A(object):
def f(self): return "A"
class B(A):
pass
class C(A):
def f(self): return "C"
class D(B, C):
pass
self.assertEqual(D.mro(), [D, B, C, A, object])
self.assertEqual(D.__mro__, (D, B, C, A, object))
self.assertEqual(D().f(), "C")
class PerverseMetaType(type):
def mro(cls):
L = type.mro(cls)
L.reverse()
return L
class X(D,B,C,A):
__metaclass__ = PerverseMetaType
self.assertEqual(X.__mro__, (object, A, C, B, D, X))
self.assertEqual(X().f(), "A")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return [self, dict, object]
# In CPython, the class creation above already raises
# TypeError, as a protection against the fact that
# instances of X would segfault it. In other Python
# implementations it would be ok to let the class X
# be created, but instead get a clean TypeError on the
# __setitem__ below.
x = object.__new__(X)
x[5] = 6
except TypeError:
pass
else:
self.fail("devious mro() return not caught")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return [1]
except TypeError:
pass
else:
self.fail("non-class mro() return not caught")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return 1
except TypeError:
pass
else:
self.fail("non-sequence mro() return not caught")
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
class WorkOnce(type):
def __new__(self, name, bases, ns):
self.flag = 0
return super(WorkOnce, self).__new__(WorkOnce, name, bases, ns)
def mro(self):
if self.flag > 0:
raise RuntimeError, "bozo"
else:
self.flag += 1
return type.mro(self)
class WorkAlways(type):
def mro(self):
# this is here to make sure that .mro()s aren't called
# with an exception set (which was possible at one point).
# An error message will be printed in a debug build.
# What's a good way to test for this?
return type.mro(self)
class C(object):
pass
class C2(object):
pass
class D(C):
pass
class E(D):
pass
class F(D):
__metaclass__ = WorkOnce
class G(D):
__metaclass__ = WorkAlways
# Immediate subclasses have their mro's adjusted in alphabetical
# order, so E's will get adjusted before adjusting F's fails. We
# check here that E's gets restored.
E_mro_before = E.__mro__
D_mro_before = D.__mro__
try:
D.__bases__ = (C2,)
except RuntimeError:
self.assertEqual(E.__mro__, E_mro_before)
self.assertEqual(D.__mro__, D_mro_before)
else:
self.fail("exception not propagated")
def test_altmro(self):
# Testing mro() and overriding it...
class A(object):
def f(self): return "A"
class B(A):
pass
class C(A):
def f(self): return "C"
class D(B, C):
pass
self.assertEqual(D.mro(), [D, B, C, A, object])
self.assertEqual(D.__mro__, (D, B, C, A, object))
self.assertEqual(D().f(), "C")
class PerverseMetaType(type):
def mro(cls):
L = type.mro(cls)
L.reverse()
return L
class X(D,B,C,A):
__metaclass__ = PerverseMetaType
self.assertEqual(X.__mro__, (object, A, C, B, D, X))
self.assertEqual(X().f(), "A")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return [self, dict, object]
# In CPython, the class creation above already raises
# TypeError, as a protection against the fact that
# instances of X would segfault it. In other Python
# implementations it would be ok to let the class X
# be created, but instead get a clean TypeError on the
# __setitem__ below.
x = object.__new__(X)
x[5] = 6
except TypeError:
pass
else:
self.fail("devious mro() return not caught")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return [1]
except TypeError:
pass
else:
self.fail("non-class mro() return not caught")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return 1
except TypeError:
pass
else:
self.fail("non-sequence mro() return not caught")
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
class WorkOnce(type):
def __new__(self, name, bases, ns):
self.flag = 0
return super(WorkOnce, self).__new__(WorkOnce, name, bases, ns)
def mro(self):
if self.flag > 0:
raise RuntimeError, "bozo"
else:
self.flag += 1
return type.mro(self)
class WorkAlways(type):
def mro(self):
# this is here to make sure that .mro()s aren't called
# with an exception set (which was possible at one point).
# An error message will be printed in a debug build.
# What's a good way to test for this?
return type.mro(self)
class C(object):
pass
class C2(object):
pass
class D(C):
pass
class E(D):
pass
class F(D):
__metaclass__ = WorkOnce
class G(D):
__metaclass__ = WorkAlways
# Immediate subclasses have their mro's adjusted in alphabetical
# order, so E's will get adjusted before adjusting F's fails. We
# check here that E's gets restored.
E_mro_before = E.__mro__
D_mro_before = D.__mro__
try:
D.__bases__ = (C2,)
except RuntimeError:
self.assertEqual(E.__mro__, E_mro_before)
self.assertEqual(D.__mro__, D_mro_before)
else:
self.fail("exception not propagated")
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
class WorkOnce(type):
def __new__(self, name, bases, ns):
self.flag = 0
return super(WorkOnce, self).__new__(WorkOnce, name, bases, ns)
def mro(self):
if self.flag > 0:
raise RuntimeError("bozo")
else:
self.flag += 1
return type.mro(self)
class WorkAlways(type):
def mro(self):
# this is here to make sure that .mro()s aren't called
# with an exception set (which was possible at one point).
# An error message will be printed in a debug build.
# What's a good way to test for this?
return type.mro(self)
class C(object):
pass
class C2(object):
pass
class D(C):
pass
class E(D):
pass
class F(D, metaclass=WorkOnce):
pass
class G(D, metaclass=WorkAlways):
pass
# Immediate subclasses have their mro's adjusted in alphabetical
# order, so E's will get adjusted before adjusting F's fails. We
# check here that E's gets restored.
E_mro_before = E.__mro__
D_mro_before = D.__mro__
try:
D.__bases__ = (C2,)
except RuntimeError:
self.assertEqual(E.__mro__, E_mro_before)
self.assertEqual(D.__mro__, D_mro_before)
else:
self.fail("exception not propagated")
def test_altmro(self):
# Testing mro() and overriding it...
class A(object):
def f(self): return "A"
class B(A):
pass
class C(A):
def f(self): return "C"
class D(B, C):
pass
self.assertEqual(D.mro(), [D, B, C, A, object])
self.assertEqual(D.__mro__, (D, B, C, A, object))
self.assertEqual(D().f(), "C")
class PerverseMetaType(type):
def mro(cls):
L = type.mro(cls)
L.reverse()
return L
class X(D,B,C,A):
__metaclass__ = PerverseMetaType
self.assertEqual(X.__mro__, (object, A, C, B, D, X))
self.assertEqual(X().f(), "A")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return [self, dict, object]
# In CPython, the class creation above already raises
# TypeError, as a protection against the fact that
# instances of X would segfault it. In other Python
# implementations it would be ok to let the class X
# be created, but instead get a clean TypeError on the
# __setitem__ below.
x = object.__new__(X)
x[5] = 6
except TypeError:
pass
else:
self.fail("devious mro() return not caught")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return [1]
except TypeError:
pass
else:
self.fail("non-class mro() return not caught")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return 1
except TypeError:
pass
else:
self.fail("non-sequence mro() return not caught")
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
class WorkOnce(type):
def __new__(self, name, bases, ns):
self.flag = 0
return super(WorkOnce, self).__new__(WorkOnce, name, bases, ns)
def mro(self):
if self.flag > 0:
raise RuntimeError, "bozo"
else:
self.flag += 1
return type.mro(self)
class WorkAlways(type):
def mro(self):
# this is here to make sure that .mro()s aren't called
# with an exception set (which was possible at one point).
# An error message will be printed in a debug build.
# What's a good way to test for this?
return type.mro(self)
class C(object):
pass
class C2(object):
pass
class D(C):
pass
class E(D):
pass
class F(D):
__metaclass__ = WorkOnce
class G(D):
__metaclass__ = WorkAlways
# Immediate subclasses have their mro's adjusted in alphabetical
# order, so E's will get adjusted before adjusting F's fails. We
# check here that E's gets restored.
E_mro_before = E.__mro__
D_mro_before = D.__mro__
try:
D.__bases__ = (C2,)
except RuntimeError:
self.assertEqual(E.__mro__, E_mro_before)
self.assertEqual(D.__mro__, D_mro_before)
else:
self.fail("exception not propagated")
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
class WorkOnce(type):
def __new__(self, name, bases, ns):
self.flag = 0
return super(WorkOnce, self).__new__(WorkOnce, name, bases, ns)
def mro(self):
if self.flag > 0:
raise RuntimeError("bozo")
else:
self.flag += 1
return type.mro(self)
class WorkAlways(type):
def mro(self):
# this is here to make sure that .mro()s aren't called
# with an exception set (which was possible at one point).
# An error message will be printed in a debug build.
# What's a good way to test for this?
return type.mro(self)
class C(object):
pass
class C2(object):
pass
class D(C):
pass
class E(D):
pass
class F(D, metaclass=WorkOnce):
pass
class G(D, metaclass=WorkAlways):
pass
# Immediate subclasses have their mro's adjusted in alphabetical
# order, so E's will get adjusted before adjusting F's fails. We
# check here that E's gets restored.
E_mro_before = E.__mro__
D_mro_before = D.__mro__
try:
D.__bases__ = (C2,)
except RuntimeError:
self.assertEqual(E.__mro__, E_mro_before)
self.assertEqual(D.__mro__, D_mro_before)
else:
self.fail("exception not propagated")
def test_altmro(self):
# Testing mro() and overriding it...
class A(object):
def f(self): return "A"
class B(A):
pass
class C(A):
def f(self): return "C"
class D(B, C):
pass
self.assertEqual(D.mro(), [D, B, C, A, object])
self.assertEqual(D.__mro__, (D, B, C, A, object))
self.assertEqual(D().f(), "C")
class PerverseMetaType(type):
def mro(cls):
L = type.mro(cls)
L.reverse()
return L
class X(D,B,C,A):
__metaclass__ = PerverseMetaType
self.assertEqual(X.__mro__, (object, A, C, B, D, X))
self.assertEqual(X().f(), "A")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return [self, dict, object]
# In CPython, the class creation above already raises
# TypeError, as a protection against the fact that
# instances of X would segfault it. In other Python
# implementations it would be ok to let the class X
# be created, but instead get a clean TypeError on the
# __setitem__ below.
x = object.__new__(X)
x[5] = 6
except TypeError:
pass
else:
self.fail("devious mro() return not caught")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return [1]
except TypeError:
pass
else:
self.fail("non-class mro() return not caught")
try:
class X(object):
class __metaclass__(type):
def mro(self):
return 1
except TypeError:
pass
else:
self.fail("non-sequence mro() return not caught")
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
class WorkOnce(type):
def __new__(self, name, bases, ns):
self.flag = 0
return super(WorkOnce, self).__new__(WorkOnce, name, bases, ns)
def mro(self):
if self.flag > 0:
raise RuntimeError, "bozo"
else:
self.flag += 1
return type.mro(self)
class WorkAlways(type):
def mro(self):
# this is here to make sure that .mro()s aren't called
# with an exception set (which was possible at one point).
# An error message will be printed in a debug build.
# What's a good way to test for this?
return type.mro(self)
class C(object):
pass
class C2(object):
pass
class D(C):
pass
class E(D):
pass
class F(D):
__metaclass__ = WorkOnce
class G(D):
__metaclass__ = WorkAlways
# Immediate subclasses have their mro's adjusted in alphabetical
# order, so E's will get adjusted before adjusting F's fails. We
# check here that E's gets restored.
E_mro_before = E.__mro__
D_mro_before = D.__mro__
try:
D.__bases__ = (C2,)
except RuntimeError:
self.assertEqual(E.__mro__, E_mro_before)
self.assertEqual(D.__mro__, D_mro_before)
else:
self.fail("exception not propagated")
def test_mutable_bases_with_failing_mro(self):
# Testing mutable bases with failing mro...
class WorkOnce(type):
def __new__(self, name, bases, ns):
self.flag = 0
return super(WorkOnce, self).__new__(WorkOnce, name, bases, ns)
def mro(self):
if self.flag > 0:
raise RuntimeError("bozo")
else:
self.flag += 1
return type.mro(self)
class WorkAlways(type):
def mro(self):
# this is here to make sure that .mro()s aren't called
# with an exception set (which was possible at one point).
# An error message will be printed in a debug build.
# What's a good way to test for this?
return type.mro(self)
class C(object):
pass
class C2(object):
pass
class D(C):
pass
class E(D):
pass
class F(D, metaclass=WorkOnce):
pass
class G(D, metaclass=WorkAlways):
pass
# Immediate subclasses have their mro's adjusted in alphabetical
# order, so E's will get adjusted before adjusting F's fails. We
# check here that E's gets restored.
E_mro_before = E.__mro__
D_mro_before = D.__mro__
try:
D.__bases__ = (C2,)
except RuntimeError:
self.assertEqual(E.__mro__, E_mro_before)
self.assertEqual(D.__mro__, D_mro_before)
else:
self.fail("exception not propagated")
