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Date: Thu, 20 Sep 2012 18:58:21 -0400 (EDT)
Subject: Functional way to compare things inside a list
From: thorsopia@lavabit.com
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Xref: csiph.com comp.lang.python:29604

Hi,

list = [{'1': []}, {'2': []}, {'3': ['4', '5']}]

I want to check for a value (e.g. '4'), and get the key of the dictionary
that contains that value.
(Yep, this is bizarre.)

some_magic(list, '4')
=> '3'

What's the functional way to do it?
Is it possible to do it with a one-liner?