looking up dictionaries by values
steve at holdenweb.com
Fri Mar 11 04:32:07 CET 2005
> Hi there,
> I'm still a bit new to Python, and had a question.
> I have a dictionary that looks like:
> PWD = \
> "root": 0,
> "joe": 200,
> "susan": 201,
> In other words, the values are unique as well as the keys. I've run
> into a situation where I need to lookup the item by value. So given
> 201, I need to say the key is really susan.
> Is there a way to do this that does not traverse the entire dictionary
> multiple times?
One way would be to keep two parallel dictionaries so you have both
mappings. If necessary you could wrap this up as an object to make it
easier to deal with.
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