Real-world use cases for map's None fill-in feature?

Paul Rubin http
Fri Jan 13 05:12:10 CET 2006

"Raymond Hettinger" <python at> writes:
> > I see at least a few cases of
> >     map(None, field_names, values)
> > but it's not clear what the expectation is for the size of the two lists.
> Thanks for the additional datapoint.  I'm most interested in the code
> surrounding the few cases with multiple inputs and whether the code is
> designed around equal or unequal length inputs.  The existence of the
> latter is good news for the proposal.  Its absence would be a
> contra-indication.  If you get a chance, please look at those few
> multi-input cases.

ISTR there's also a plan to eliminate map in Python 3.0 in favor of
list comprehensions.  That would get rid of the possibility of using
map(None...) instead of izip_longest.  This needs to be thought through.

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