map-like function on dict values?

Carel Fellinger cfelling at
Wed Feb 27 22:45:34 EST 2002

Huaiyu Zhu <huaiyu at> wrote:
> Is there a way to do this

> for k, v in dict.items():
>     dict[k] = f(v)

> without involving a Python for loop?  I'd imagine that a function
> implemented in C could speed things up quite a bit.  Something like

what about using an iterator, like

  for k, v in dict.iteritems():
      dict[k] = f(v)

would be interesting to know whether saving to build a (huge) list would
save you the time you need.

As for the C function, for each item you'll have to get to the python
interpreter to evaluate the `f(v)' call. My gut feeling would be that
that would be costly. But as you know, gut feelings are worthless,
time it instead.

groetjes, carel

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