Python list comprehension - simple

Question

I have a list and I want to use a certain function only on those entries of it that fulfills a certain condition - leaving the other entries unmodified.

Example: Say

Answer 1

You could use lambda:

>>> a_list = [1, 2, 3, 4, 5]
>>> f = lambda x: x%2 and x or x*2
>>> a_list = [f(i) for i in a_list]
>>> a_list
[1, 4, 3, 8, 5]

Edit - Thinking about agf's remark I made a 2nd version of my code:

>>> a_list = [1, 2, 3, 4, 5]
>>> f = lambda x: x if x%2 else x*2
>>> a_list = [f(i) for i in a_list]
>>> a_list
[1, 4, 3, 8, 5]