item系列及定制str、repr

class Foo:
    def __getitem__(self, item):
        print(‘正在执行getitem‘,item)
        return self.__dict__[item]

    def __setitem__(self, key, value):
        print(‘正在执行setitem‘)
        self.__dict__[key] = value

    def __delitem__(self, key):
        print(‘正在执行delitem‘)
        self.__dict__.pop(key)

f1 = Foo()
print(f1.__dict__)
f1[‘name‘] = ‘jinling‘
print(f1.__dict__)
f1[‘age‘] = 19
print(f1[‘age‘])
print(f1.__dict__)
del f1[‘age‘]
print(f1.__dict__)

class Foo:
    def __init__(self,name,age):
        self.name = name
        self.age = age
    def __str__(self):
        return ‘名字是{} 年龄是{}‘.format(self.name,self.age)

f1 = Foo(‘jinling‘, 19)
print(f1)  # -->str(f1)-->f1.__str__()

class Foo:
    def __init__(self,name,age):
        self.name = name
        self.age = age
    def __str__(self):
        return "print会触发这个哦"
    def __repr__(self):
        return ‘名字是{} 年龄是{}‘.format(self.name,self.age)

f1 = Foo(‘jinling‘, 19)
print(f1)  # -->str(f1)-->f1.__str__()

class Foo:
    def __init__(self,name,age):
        self.name = name
        self.age = age
    # def __str__(self):
    #     return "print会触发这个哦"
    def __repr__(self):
        return ‘名字是{} 年龄是{}‘.format(self.name,self.age)

f1 = Foo(‘jinling‘, 19)
print(f1)  # -->str(f1)-->f1.__str__()---->f1.__repr__()