Gerald Britton <gerald.brit...@gmail.com> wrote: > I find: > > map(func, iterable) > > to be "neater" than: > > [func(item) for item in iterable] > > If nothing else, the "map" version is shorter.
That's only true if you wanted to call an existing function. If you wanted to do something involving a more complex expression that you can write inline then the list comprehension is shorter. <snip> > Also, as already shown, the map version is faster. In most cases the list comprehension is faster. Try timing it. C:\Python27>python.exe lib\timeit.py -s "def double(x): return x*2" -s "data=range(10000)" "map(double, data)" 1000 loops, best of 3: 1.82 msec per loop C:\Python27>python.exe lib\timeit.py -s "def double(x): return x*2" -s "data=range(10000)" "[x*2 for x in data]" 1000 loops, best of 3: 879 usec per loop map is only likely to be faster if you wanted to call a function in both cases. If you have an expression that can be inlined you save the function call overhead with the list comprehension. -- Duncan Booth http://kupuguy.blogspot.com -- http://mail.python.org/mailman/listinfo/python-list
