python之反射

python之反射
公共代码：

class Dog(object):
	'''定义了一个Dog的类，有一个shout方法，并创建了一个名字为HaBa的dog实例'''
    def __init__(self,name):
        self.name=name

    def shout(self):
        print("The dog is shouting:Wang Wang Wang")
        
    def eat(self,food):
        print("The dog is eating %s"%food)

dog=Dog("HaBa")
choice=input("input your choice:")

1.hasattr(obj,string)
判断对象obj中有没有名字是string的方法，返回布尔值

result=hasattr(dog,choice)
print("result=",result)

运行结果

input your choice:shout
result= True

2.getattr(obj,string)
从对象obj中获得名字为string的方法，返回方法的地址

fun=getattr(dog,choice)
dog_food="gutou"
fun(dog_food)

运行结果

input your choice:eat
The dog is eating gutou

3.setattr(obj,x,value)
等价于obj.x=value，即给对象中的x赋值为value。

setattr(dog,choice,dog_sleep)
fun2=getattr(dog,choice)
fun2(dog)

运行结果

input your choice:sleep
HaBa is sleeping...

4.delattr(obj,x)
删除对象obj中的x

if hasattr(dog,choice):
    delattr(dog,choice)
    print("%s"%dog.name)
else:
    print("your choice isn't exist!")

运行结果

input your choice:name
Traceback (most recent call last):
  File "E:/Code/python workplace/project/类/反射.py", line 34, in <module>
    print("%s"%dog.name)
AttributeError: 'Dog' object has no attribute 'name'