反射181113

反射

• hasattr(obj,name_str)：判读一个对象里是否有指定对应的字符串的方法
• getattr(obj,name_str)：获取对象中字符串方法的字符串地址
• setattr(obj,'y',v)：setattr(x, 'y', v) is equivalent to ``x.y = v''

# Author:Li Dongfei
class Dog(object):

    def __init__(self,name):
        self.name = name

    def eat(self,food):
        print("%s is eating %s." %(self.name,food))

d = Dog("旺财")
choice = input(">>>: ".strip())

print(hasattr(d,choice))  #判断d有没有$choice的属性
#print(getattr(d,choice))  #获取内存对象地址
#getattr(d,choice)()  #加()来调用执行

if hasattr(d,choice):
    func = getattr(d,choice)
    func("baozi")

• delattr：删除

# Author:Li Dongfei
class Dog(object):

    def __init__(self,name):
        self.name = name

    def eat(self,food):
        print("%s is eating %s." %(self.name,food))

d = Dog("旺财")
choice = input(">>>: ".strip())

print(hasattr(d,choice))  #判断d有没有$choice的属性
#print(getattr(d,choice))  #获取内存对象地址
#getattr(d,choice)()  #加()来调用执行

if hasattr(d,choice):
    delattr(d,choice)
print(d.name)

• setattr

# Author:Li Dongfei

def bulk(self):
    print("%s is wangwang" %self.name)

class Dog(object):

    def __init__(self,name):
        self.name = name

    def eat(self,food):
        print("%s is eating %s." %(self.name,food))

d = Dog("旺财")
choice = input(">>>: ".strip())

print(hasattr(d,choice))  #判断d有没有$choice的属性
#print(getattr(d,choice))  #获取内存对象地址
#getattr(d,choice)()  #加()来调用执行

if hasattr(d,choice):
    func = getattr(d,choice)
else:
    setattr(d,choice,bulk)
    d.talk(d)

• 加一个新属性

# Author:Li Dongfei
def bulk(self):
    print("%s is wangwang" %self.name)

class Dog(object):

    def __init__(self,name):
        self.name = name

    def eat(self,food):
        print("%s is eating %s." %(self.name,food))

d = Dog("旺财")
choice = input(">>>: ".strip())

if hasattr(d,choice):
    getattr(d,choice)
else:
    setattr(d,choice,None)
    v = getattr(d,choice)
    print(v)

# Author:Li Dongfei
def bulk(self):
    print("%s is wangwang" %self.name)

class Dog(object):

    def __init__(self,name):
        self.name = name

    def eat(self,food):
        print("%s is eating %s." %(self.name,food))

d = Dog("旺财")
choice = input(">>>: ".strip())

if hasattr(d,choice):
    getattr(d,choice)
else:
    setattr(d,choice,bulk)
    func = getattr(d,choice)
    func(d)