more pythonic

[Alan Isaac]

Paul McGuire wrote:

> In general, whenever you have:

>     someNewList = []

>     for smthg in someSequence:

>         if condition(smthg):

>             someNewList.append( elementDerivedFrom(smthg) )



> replace it with:

>     someNewList = [ elementDerivedFrom(smthg)

>                       for smthg in someSequence

>                         if condition(smthg) ]







What is the gain?  (Real question.)

I think the first is often easier to read.

Is the second more efficient?



Also, I think list comprehensions are often easier to read

as equivalent generator expressions:



      someNewList = list( elementDerivedFrom(smthg)

                            for smthg in someSequence

                              if condition(smthg) )



Tastes vary of course.



Cheers,

Alan Isaac