python - 类的str

class Foo:
    #构造方法
    def __init__(self,name,age):
        pass
        self.name = name
        self.age = age
   
    def __str__(self):
        return "%s - %d" %(self.name,self.age)

obj1 = Foo(‘alex‘,73)
obj2 = Foo(‘eric‘,84)
print(obj1)

class Foo:
    #构造方法
    def __init__(self,name,age):
        pass
        self.name = name
        self.age = age
    def __getitem__(self, item):
        return 123

obj = Foo(‘alex‘,73)
ret = obj[‘ab‘]
print(ret)

class Foo:
    #构造方法
    def __init__(self,name,age):
        pass
        self.name = name
        self.age = age

    def __getitem__(self, item):
        print(item.start)
        print(item.stop)
        print(item.step)

   
obj = Foo(‘alex‘,73)

ret2 = obj[1:4:2]

class Foo:
    #构造方法
    def __init__(self,name,age):
        pass
        self.name = name
        self.age = age
    def __getitem__(self, item):
        return 123

    def __setitem__(self, key, value):
        print(‘setitem‘)


obj = Foo(‘alex‘,73)
obj[‘k1‘] = 111

class Foo:
    #构造方法
    def __init__(self,name,age):
        pass
        self.name = name
        self.age = age
  

    def __setitem__(self, key, value):
        print(type(key),type(value))
        print(key.start)
        print(key.stop)
        print(key.step)


obj = Foo(‘alex‘,73)

obj[1:4] = [11,22,33,44]

<class ‘slice‘> <class ‘list‘>
1
4
None

class Foo:
    #构造方法
    def __init__(self,name,age):
        pass
        self.name = name
        self.age = age
   
    def __delitem__(self, key):
        print(‘del item‘)


obj = Foo(‘alex‘,73)

del obj[‘k1‘]

class Foo:
    #构造方法
    def __init__(self,name,age):
        pass
        self.name = name
        self.age = age


    def __delitem__(self, key):
        print(type(key))
        print(key.start)
        print(key.stop)
        print(key.step)


obj = Foo(‘alex‘,73)

del obj[1:4]