Python抽象類的新寫法

class MyCls():
 def foo(self):
 print('method no implement')

運(yùn)行的例子


>>> a = MyCls()
>>> a.foo()
method no implement
>>>

class MyCls():
 def foo(self):
 raise Exception('no implement exception', 'foo method need implement')

>>> a = MyCls()
>>> a.foo()
Traceback (most recent call last):
 File "", line 1, in 
 File "", line 3, in foo
Exception: ('no implement exception', 'foo method need implement')

from abc import ABCMeta
 
from abc import ABCMeta,abstractmethod
 
class Foo():
 __metaclass__ = ABCMeta
 @abstractmethod
 def bar(self):
 pass

>>> class B(Foo):
... def bar(self):
... pass
... 
>>> B()
<__main__.B object at 0x02EE7B50>
>>> B().bar()
>>> class C(Foo):
... pass
... 
>>> C().bar()
Traceback (most recent call last):
 File "", line 1, in 
TypeError: Can't instantiate abstract class C with abstract methods bar
>>>