面向对象——反射

1 def getattr(object, name, default=None): # known special case of getattr
2     """
3     getattr(object, name[, default]) -> value
4 
5     Get a named attribute from an object; getattr(x, ‘y‘) is equivalent to x.y.
6     When a default argument is given, it is returned when the attribute doesn‘t
7     exist; without it, an exception is raised in that case.
8     """
9     pass

1 def setattr(x, y, v): # real signature unknown; restored from __doc__
2     """
3     Sets the named attribute on the given object to the specified value.
4 
5     setattr(x, ‘y‘, v) is equivalent to ``x.y = v‘‘
6     """
7     pas

1 def delattr(x, y): # real signature unknown; restored from __doc__
2     """
3     Deletes the named attribute from the given object.
4 
5     delattr(x, ‘y‘) is equivalent to ``del x.y‘‘
6     """
7     pass

 1 class People:
 2     country=‘China‘
 3 
 4     def __init__(self,name,age):
 5         self.name=name
 6         self.age=age
 7 
 8     def talk(self):
 9         print(‘%s is talking‘ %self.name)
10 obj=People(‘egon‘,18)
11 #通常情况下：
12 # print(obj.name) #egon
13 # print(obj.talk)#<bound method People.talk of <__main__.People object at 0x000000000287ACC0>>
14 #
15 # choice = input("==>:")##choice=‘name‘
16 # print(object.choice)#object.‘name‘，报错
17 #字符串映射
18 
19 #检测是否含有某属性
20 # print(hasattr(obj,‘name‘)) #True
21 # print(hasattr(obj,‘talk‘)) #True
22 # print(hasattr(obj,‘run‘))#False
23 
24 #获取属性
25 # print(getattr(obj,‘name‘))#egon
26 # print(getattr(obj,‘run‘))#报错
27 # print(getattr(obj,‘run‘,None))#None
28 # fun = getattr(obj,‘talk‘)
29 # fun()#egon is talking
30 
31 #设置属性
32 setattr(obj,‘sex‘,‘male‘)  #obj.sex = male
33 print(obj.sex)#male
34 setattr(obj,‘show_name‘,lambda self : self.name+‘_s‘)#设置方法
35 print(obj.show_name(obj))#egon_s
36 print(obj.__dict__)
37 #{‘name‘: ‘egon‘, ‘age‘: 18, ‘sex‘: ‘male‘, ‘show_name‘: <function <lambda> at 0x0000000001CF2E18>}
38 
39 #删除属性
40 delattr(obj,‘age‘)
41 delattr(obj,‘show_name‘)
42 print(obj.__dict__)#{‘name‘: ‘egon‘, ‘sex‘: ‘male‘}
43 delattr(obj,‘age‘)#不存在，则报错

class Foo:
    staticField = ‘old boy‘
    def __init__(self):
        self.name = ‘wupeiqi‘
    @classmethod
    def func(self):
        return ‘func‘
    @staticmethod
    def bar():
        return ‘bar‘
print(getattr(Foo,‘staticField‘))#old boy
print(getattr(Foo,‘func‘))#<bound method Foo.func of <class ‘__main__.Foo‘>>
print(getattr(Foo,‘bar‘))#<function Foo.bar at 0x0000000001E84510>