[Python-Dev] Adding concat function to itertools (original) (raw)

Mike Klaas mike.klaas at gmail.com
Fri Sep 28 23:40:08 CEST 2007

On 28-Sep-07, at 10:45 AM, Raymond Hettinger wrote:

[Bruce Frederiksen]

I've added a new function to itertools called 'concat'. This function is much like chain, but takes all of the iterables as a single argument. Any practical use cases or is this just a theoretical improvement? For Py2.x, I'm not willing to unnecessarily expand the module. However, for Py3k, I'm open to changing the signature for chain().

For me, a fraction of chain() uses are of the * variety:

d = defaultdict(list) allvals = chain(*d.values())

return chain(*imap(cache.getitem, keylist))

Interestingly, they seem to all have something to do with dictionary
values() that are themselves iterable.

-Mike

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