[Tutor] Question about Dictionaries

[Chorn, Guillaume]

Thanks Dave.  Actually I figured out a relatively simple solution to my
specific problem--since the dictionary I made was the result of zipping
together two lists, I simply made a second dictionary with the lists
switched around after the zip command and used that.  It worked in my
case because all key-value pairings were unique... 

-----Original Message-----
From: Dave Angel [mailto:davea at ieee.org] 
Sent: Monday, August 16, 2010 4:03 PM
To: Chorn, Guillaume
Cc: tutor at python.org
Subject: Re: [Tutor] Question about Dictionaries

Chorn, Guillaume wrote:
> Hi All,
>
> I know that I can look up the value for a particular key in a
> dictionary, but can I look up the key associated with a particular
> value?  I understand that this could be problematic from the
standpoint
> of multiple keys having the same value, but even then I feel like
Python
> could just return a list of keys with that value.
>
> Thanks!
>
> Guillaume  
>
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>   
As long as you don't mind it being (relatively) slow, you could do 
something like (untested):

[key for key, item in mydict if item == value]

DaveA


Notice:  This e-mail message, together with any attachments, contains
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