Python Golfing - Narrow function calling on array down [closed]

Question

Say i have a function named J and an array named f.

now i call this code:

result = []
for n in f:
    results.append(J(n))

is there any more efficient way of doing this? I was thinking something along the lines of...

results = (J(n) for n in f)

But that didn't work.

Answer 1

r=map(J,f)

is probably the shortest you can get (although it's unclear what you want here; the example you give works, it just creates a generator instead of a list. Use [], not () for a list comprehension.

Answer 2

If n and(/or) f are mutable and J can be altered then you could run just for n in f: J(n). If that isn't possible then your original idea should be the most efficient computation-wise. Map does the same in fewer letters making it more efficient golf-wise.