python - 如何删除列表中的整个字典？

Question

mylist = [{"a" : 1, " b" : 2}, {"c" : 1, "d" :2}]

我的 list 是这样的。我将如何删除包含键“a”的整个字典？

Answer 1

您可以使用 list comprehension 使用 dict 来创建一个新列表，而无需 'a' 键，如下所示:

>>> mylist = [{"a" : 1, " b" : 2},{"c" : 1, "d" :2}]

>>> [d for d in mylist if 'a' not in d]
[{'c': 1, 'd': 2}]

如果必须从原始列表中删除元素，那么您可以这样做:

>>> mylist = [{"a" : 1, " b" : 2},{"c" : 1, "d" :2}]

#                           v Iterate over the copy of the list,
#                           v    so that the change in index after the 
#                           v    deletion of  elements in the list won't 
#                           v    impact the future iterations
>>> for i, d in enumerate(list(mylist)):
...     if 'a' in d:
...         del mylist[i]
...
>>> mylist
[{'c': 1, 'd': 2}]