python - 从列表中字典中的值中减去python

我有一个字典列表，想从列表中所有字典的键“质量”的值中减去1

list=[{key1:xx, key2:xx, quality:5},{key1:xx, key2:xx, quality:5},{key1:xx, key2:xx, quality:5}]

并希望得到

list=[{key1:xx, key2:xx, quality:4},{key1:xx, key2:xx, quality:4},{key1:xx, key2:xx, quality:4}]

我试过了

list=[(i['quality']-1 for i in list]

但是没用

在此先感谢您的帮助！

最佳答案

采取直接方法怎么样：

>>> l = [{'a':'aa', 'b':'bb', 'quality':5},{'c':'cc', 'd':'dd', 'quality':5},{'e':'ee', 'f':'ff', 'quality':5}]
>>> for item in l:
...     item['quality'] -= 1
...
>>> l
[{'a': 'aa', 'b': 'bb', 'quality': 4}, {'c': 'cc', 'quality': 4, 'd': 'dd'}, {'quality': 4, 'e': 'ee', 'f': 'ff'}]