清单的Python属性和设置器（如int和string）

Question

I have a class with variables ( int , string and list ). And I would like to use @property to get value of variables, setter to set values to this variables. I could implement this conception for int and string variables, but not for list . Please, help me to implement it for list too.

class MyClass:

    def __init__(self):
        self._a = 1
        self._b = 'hello'
        self._c = [1, 2, 3]

    @property
    def a(self):
        print(self._a)

    @a.setter
    def a(self, a):
        self._a = a

    @property
    def b(self):
        print(self._b)

    @b.setter
    def b(self, b):
        self._b = b


my = MyClass()

my.a
# Output: 1
my.a = 2
my.a
# Output: 2

my.b
# Output: hello
my.b = 'world'
my.b
# Output: world


# Need to implement:
my.c
# Output: [1, 2, 3]
my.c = [4, 5, 6]
my.c
# Output: [4, 5, 6]
my.c[0] = 0
my.c
# Output: [0, 5, 6]
my.c[0]
# Output: 0

I have found similar questions, but they don't suit for me, because in this way calling operations for list would differ from int and string:

• Python decorating property setter with list

• Python property on a list

Answer 1

So I believe your misunderstanding stems from not realizing that everything in python is an object. There is no difference between the list , the string or the int . Note that in your implementation for the int and the string there is no difference, except for some names.

I have recast your example with a single property, and then assigned all of your use cases to it to verify that it works in all cases.

Code:

class MyClass:
    def __init__(self):
        self.my_prop = None

    @property
    def my_prop(self):
        return self._my_prop

    @my_prop.setter
    def my_prop(self, my_prop):
        self._my_prop = my_prop

Test Code:

my = MyClass()

my.my_prop = 1
assert 1 == my.my_prop
my.my_prop = 2
assert 2 == my.my_prop

my.my_prop = 'hello'
assert 'hello' == my.my_prop
my.my_prop = 'world'
assert 'world' == my.my_prop

my.my_prop = [1, 2, 3]
assert [1, 2, 3] == my.my_prop
my.my_prop = [4, 5, 6]
assert [4, 5, 6] == my.my_prop
my.my_prop[0] = 0
assert [0, 5, 6] == my.my_prop
assert 0 == my.my_prop[0]