Python @property 异常行为：调试器引发self.updated误更新

我实现了一个管理单词集合的Universe类，通过@property装饰器定义了uncertainty属性，用于计算集合的不确定性。在使用+=运算符添加元素时，会将实例的self.updated标记为False，但调试过程中发现self.updated始终保持True；当我移除@property装饰器，将uncertainty改为普通方法后，程序行为符合预期。

最终定位到问题根源：Visual Studio Code调试器会自动调用类的@property属性，这会触发uncertainty属性的计算逻辑，从而把self.updated重新设为True，干扰了原本的状态判断。

完整代码示例 #

import math
from typing import Self
import re

FREQUENCIES: dict[str, float] = {}
FREQUENCIES['trial'] = 0.023
FREQUENCIES['raise'] = 0.124

def entropy(probability: float) -> float:
  if probability == 0.0: return 0.0
  return -probability*math.log(probability)/math.log(2.0)

class Word(str):
  def __new__(cls, value: str = 'aaaaa') -> Self:
    value = value.strip().lower()
    if not re.match(r'[a-z]{5}', value): raise ValueError(f'"{value}" does not follow the pattern [a-z]{5}!')
    return super().__new__(cls, value)
  def __init__(self, value: str = 'aaaaa') -> None:
    self.frequency = FREQUENCIES[value]

class Universe(set[Word]):
  def __init__(self) -> None:
    super().__init__(set())
    self.frequency = 0.0
    self.statistics: dict[int, dict[str, float]] = {}
    self.updated = True
  def __iadd__(self, word: Word) -> Self:
    if word in self: return self
    self.updated = False
    self.add(word)
    return self
  @property
  def uncertainty(self) -> float:
    if not self.updated:
       self.frequency = sum(word.frequency for word in self)
       self.statistics = {i: {chr(letter): sum(wordle.frequency for wordle in self if wordle[i] == chr(letter)) for letter in range(ord('a'), ord('z')+1)} for i in range(len(Word()))}
       self.updated = True
    return sum(sum(entropy(letterFrequency/self.frequency) for letterFrequency in self.statistics[position].values()) for position in self.statistics) 

使用示例 #

universe = Universe()
universe += Word('trial')
universe += Word('raise')
print(f'My universe has {len(universe)} words and an uncertainty of {universe.uncertainty} bits.')

内容的提问来源于stack exchange，提问作者Nuno