奇怪的行为代码(用Python 2.7.3测试):
class Meta1(type):
def __new__(mcl, name, bases, attrs):
print "Hello Meta1.__new__ "
return super(Meta1, mcl).__new__(mcl, name, bases, attrs)
class Meta2(type):
def __new__(mcl, name, bases, attrs):
print "Hello Meta2.__new__ "
return super(Meta2, mcl).__new__(
type, # looks to cause all strange behavior, but anyway pass type here, not mcl
name, bases, attrs)
print "Declaring BaseClass1"
class BaseClass1(object):
__metaclass__ = Meta1
print "-----------------------"
print "Declaring BaseClass2"
class BaseClass2(BaseClass1):
__metaclass__ = Meta2
print "-----------------------"
print BaseClass2.__class__
它的输出:
Declaring BaseClass1
Hello Meta1.__new__
-----------------------
Declaring …