检测类属性值更改，然后更改另一个类属性 [英] Detecting class attribute value change and then changing another class attribute

问题描述

比方说我有一个叫做Number的课

Let's say I have a class called Number

class Number():
  def __init__(self,n):
    self.n=n
    self.changed=None
a = Number(8)
print(a.n) #prints 8
a.n=9
print(a.n) #prints 9

当 n 类属性更改时，我希望将 changed 类属性更改为 True .

When the n class attribute changes, I want the changed class attribute to be changed to True.

推荐答案

可以正确使用 @propety

class Number():
  def __init__(self,n):
    self._n=n
    self._changed=None

  @property
  def n(self):
      return self._n

  @property
  def changed(self):
      return self._changed

  @n.setter
  def n(self, val):
      # while setting the value of n, change the 'changed' value as well
      self._n = val
      self._changed = True

a = Number(8)
print(a.n) #prints 8
a.n=9
print(a.n) #prints 9
print(a.changed)

返回:

8
9
True

这篇关于检测类属性值更改，然后更改另一个类属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！