从python中的字典中删除某些键 [英] Remove certain keys from a dictionary in python

问题描述

我正在尝试构建一个包含一系列集合的字典：

I'm trying to construct a dictionary that contains a series of sets:

{Field1:{Value1, Value2, Value3}, Field2{Value4}}

麻烦的是，我想删除任何字段在集合中只有一个值的字典。我一直在写这样的代码：

The trouble is, I then wish to delete any fields from the dictionary that only have one value in the set. I have been writing code like this:

for field in FieldSet:
    if len(FieldSet[field]) == 1:
        del(FieldSet[field])

但是收到错误RuntimeError：字典在执行期间改变大小。 （不要惊讶，因为这正是我在做的事情。）如果我必须敲定一些解决方法，这不是全部的，最终的，但是可以这样做吗？

But receive the error "RuntimeError: dictionary changed size during execution". (Not surprising, since that's what I'm doing.) It's not the be-all and end-all if I have to knock together some sort of workaround, but is it possible to do this?

推荐答案

迭代从 .keys（） 。由于您已经收到了钥匙列表，因此您可以在调用之后更改字典而不受影响。

Iterate over the return value from .keys() instead. Since you get a list of keys back, it won't be affected by changing the dictionary after you've called it.

这篇关于从python中的字典中删除某些键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！