python - 如何正确更新dict中的dict？（Python）

Question

我有以下代码：

some = {}
stat = {'matches_played': 0, 'won': 0, 'draws': 0, 'loss': 0, 'points': 0}
some = {'Arsenal': stat}
some.update({'Chelsea': stat})
some['Arsenal']['won'] += 1
some['Chelsea']['loss'] += 1
print(some)

结果是：

{'Arsenal': {'matches_played': 0, 'won': 1, 'draws': 0, 'loss': 1, 'points': 0}, 
'Chelsea': {'matches_played': 0, 'won': 1, 'draws': 0, 'loss': 1, 'points': 0}}

但是我需要

{'Arsenal': {'matches_played': 0, 'won': 1, 'draws': 0, 'loss': 0, 'points': 0}, 
'Chelsea': {'matches_played': 0, 'won': 0, 'draws': 0, 'loss': 1, 'points': 0}}

你能解释一下，为什么会这样？

标签： python

Answer 1

stat作为参考传递给关键的“切尔西”和“阿森纳”。您需要创建它的副本。

some = {}
stat = {'matches_played': 0, 'won': 0, 'draws': 0, 'loss': 0, 'points': 0}
some = {'Arsenal': stat}
some.update({'Chelsea': stat.copy()}) # <---- fix it here
some['Arsenal']['won'] += 1
some['Chelsea']['loss'] += 1
print(some)