Combining two lists into one

Question

Can you improve?

rc = []
for i, j in zip(A_response, B_response):
    rc.append(i)
    rc.append(j)

I use zip and append, but could this be better using list comprehension?

Answer 1

A good solution is in this Stack Overflow answer:

rc = [response for ab in zip(A_response, B_response) for response in ab]

Answer 2

Note that zip will not use excess elements when one list is longer than the other. For example, if one of the lists is empty and the other is not, your program will result in an empty list. I'm not sure if this was your intention. If it wasn't, then you might want to extend the result list with the excess elements of the longer list.

As @MrGrj pointed out in a comment:

You could use izip_longest for Python < 3 or zip_longest for Python >= 3. Both come from itertools module.