問題列表

• 類
• 1.1 self.__class__() 和 self.__class__
• 1.2 self.__class__()和 Class() 異同

類

1.1 self.__class__() 和 self.__class__

self.__class__就是一個類名，相當於A，類名的型別是type
self.__class__(xx)就是一個類例項，相當於呼叫A(xx)，它的型別就是A

def class_self_class():
    class A(object):
        def
 
 __init__(self,name):
            self.name = name
        def nf(self):
            print(self.__class__(self.name), type(self.__class__(self.name)), self.__class__, type(self.__class__),sep='\n')
            print(isinstance(self.__class__(self.name),self.__class__))

        def __str__(self):
            return
 
 self.name

    a = A("A")
    a.nf()
    print(type(a))
# 輸出結果
A
<class '__main__.class_self_class.<locals>.A'>
<class '__main__.class_self_class.<locals>.A'>
<class 'type'>
True
<class '__main__.class_self_class.<locals>.A'>

1.2 self.__class__()和 Class() 異同

都可以用來建立類，但是如果self.__class()__用在繼承的父類裡，能夠自動分清當前物件屬於子類還是父類？

def class_cons():
    class Foo(object):
        def create_new(self):
            return self.__class__()

        def create_new2(self):
            return Foo()
    class Bar(Foo):
        pass

    b = Bar()
    c = b.create_new()
    print(type(c))  # We got an instance of Bar

    d = b.create_new2()
    print(type(d))  # we got an instance of Foo
# 輸出結果
<class '__main__.class_cons.<locals>.Bar'>
<class '__main__.class_cons.<locals>.Foo'>