[Python] implements the common properties of the Python class

Background

Today, I see someone asking if a Python class has an attribute that is similar to a public property, which modifies the corresponding property of an instance, modifies the corresponding properties of all instances of the class, and then thinks that a class that uses an auxiliary singleton pattern solves the problem.

Ideas

Modifying an instance Another instance is also modified, which sounds like a singleton pattern, but only for one property, so you can borrow a helper class.

Code

Class Attr ():    Attr = {}    def __init__ (self):        self.__dict__ = Self.attrclass Myclass ():    def __init__ ( Self):        self.attr = attr ()    @property    def value (self):        return self.attr.value    @value. Setter    def value (self, value):        Self.attr.value = value

Demonstrate

In [the]: a = Myclass () in [1In]: b = Myclass () in [B.value]: A.value = 1In []: b.valueout[50]: []: A.V = 2In []: Alue, b.valueout[52]: (2, 2)

Feelings

Design patterns and their combinations are utilized.