英文文档：
getattr
( object
, name
[, default
] )
Return the value of the named attribute of object
. name
must be a string. If the string is the name of one of the object’s attributes, the result is the value of that attribute. For example, getattr(x, 'foobar')
is equivalent to x.foobar
. If the named attribute does not exist, default
is returned if provided, otherwiseis raised.
说明：
1. 函数功能是从对象object中获取名称为name的属性，等效与调用object.name。
#定义类Student
>>> class Student:
def __init__(self,name):
self.name = name
>>> s = Stduent('Aim')
>>> getattr(s,'name') #等效于调用s.name
'Aim'
>>> s.name
'Aim'
2. 函数第三个参数default为可选参数，如果object中含义name属性，则返回name属性的值，如果没有name属性，则返回default值，如果default未传入值，则报错。
#定义类Student >>> class Student: def __init__(self,name): self.name = name >>> getattr(s,'name') #存在属性name 'Aim' >>> getattr(s,'age',6) #不存在属性age，但提供了默认值，返回默认值 6 >>> getattr(s,'age') #不存在属性age，未提供默认值，调用报错 Traceback (most recent call last): File "<pyshell#17>", line 1, in <module> getattr(s,'age') AttributeError: 'Stduent' object has no attribute 'age'