how to create a big list of list

greg greg at
Fri Jun 5 22:20:03 EDT 2009

command.bbs at wrote:

> i have try [ [] for x in xrange(2**25) ]

Are you really going to be adding data to all
of those sublists?

If you're only using them sparsely, it may be
better to use a dictionary in place of the
top level list, and only add sublists as and
when necessary.

Recent Python versions have a built-in type
called defaultdict that makes this kind of
thing easy.


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