Python內置函數(14)——delattr

英文文檔：

delattr (object, name)

　　This is a relative of setattr(). The arguments are an object and a string. The string must be the name of one of the object’s attributes. The function deletes the named attribute, provided the object allows it. For example, delattr(x, 'foobar') is equivalent to del x.foobar.

說明：

　　

　　1. 函數作用用來刪除指定對象的指定名稱的屬性，和setattr函數作用相反。

#定義類A
>>> class A:
    def __init__(self,name):
        self.name = name
    def sayHello(self):
        print('hello',self.name)

#測試屬性和方法
>>> a.name
'小麥'
>>> a.sayHello()
hello 小麥

#刪除屬性
>>> delattr(a,'name')
>>> a.name
Traceback (most recent call last):
  File "<pyshell#47>", line 1, in <module>
    a.name
AttributeError: 'A' object has no attribute 'name'

 　　2. 當屬性不存在的時候，會報錯。

>>> a.name #屬性name已經刪掉，不存在
Traceback (most recent call last):
  File "<pyshell#47>", line 1, in <module>
    a.name
AttributeError: 'A' object has no attribute 'name'

>>> delattr(a,'name') #再刪除會報錯
Traceback (most recent call last):
  File "<pyshell#48>", line 1, in <module>
    delattr(a,'name')
AttributeError: name

 　　3. 不能刪除對象的方法。

>>> a.sayHello
<bound method A.sayHello of <__main__.A object at 0x03F014B0>>
>>> delattr(a,'sayHello') #不能用於刪除方法
Traceback (most recent call last):
  File "<pyshell#50>", line 1, in <module>
    delattr(a,'sayHello')
AttributeError: sayHello
>>>