This is actually quite elegant and useful. I've done similar things time and tim... | Hacker News

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bryanh on April 23, 2012 | parent | context | favorite | on: One-line Tree In Python

This is actually quite elegant and useful. I've done similar things time and time again with code like so:

    defaultdict(lambda: defaultdict(int))

That allows me to organically build dictionaries (mainly for stat building) using operands like +=.

joshu on April 24, 2012 [–]

Also check out collections.Counter.

  x = collections.defaultdict(collections.Counter)
  x['foo']['bar'] += 1
  X['foo'].most_common(10)
 Etc.

bryanh on April 24, 2012 | [–]

Excellent! I didn't know about that one!

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