object 和 type
python中object是所有类的基类
>>> type.__bases__
(<class 'object'>,)
class Foo(object):
pass
>>> Foo.__bases__
(<class 'object'>,)
class Boo(Foo):
pass
>>> Boo.__bases__
(<class '__main__.Foo'>,)
>>> Boo.__base__.__bases__
(<class 'object'>,)
python中一切皆对象,类也是对象,类对象是由元类创建;type是python内建元类,所有元类的祖宗,类对象可以由元类type或者元类type的子类创建
class Foo(object):
pass
>>> Foo.__class__
<class 'type'>
foo = Foo()
>>> foo.__class__
<class '__main__.Foo'>
>>> foo.__class__.__class__
<class 'type'>
type也是元类对象,由自身创建
>>> type.__class__
<class 'type'>