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Date: Thu, 23 Jan 2014 09:30:23 -0600
From: Tim Chase <python.list@tim.thechases.com>
To: python-list@python.org
Subject: Re: Initialise dictionary of dictionary
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Xref: csiph.com comp.lang.python:64617

On 2014-01-23 07:15, Ayushi Dalmia wrote:
> I need to initialise a dictionary of dictionary with float values.
> I do not know the size of the dictionary beforehand. How can we do
> that in Python --
 
Either

  d = {}

or, if you want

  from collections import defaultdict
  d = defaultdict(float)
  print(d["Hello"])

If you really do want a dict-of-dict that defaults to floats, you can
do

  d = defaultdict(lambda: defaultdict(float))
  print(d[3141]["Hello"])

-tkc