python - What does this line do? (using num and enumerate) -

i'm python beginner, , have been given code write out each line does. here code:

z = [int(input("enter nth term sequence ")) _ in range(12)] total = sum([num * 8 if % 2 == 0 else num * 4 i, num in enumerate(z)]) 

so, assume z list, user inputs numbers of nth term sequence, there 12 digits can enter. code finds sum of numbers multiplied 8 if divided 2 gives remainder of 0. don't ([num * 8 if % 2 == 0 else num * 4 i, num in enumerate(z)]) means. i've tried , have attempted search things up, it's confusing. please if possible

the code:

foo = [num * 8 if % 2 == 0 else num * 4 i, num in enumerate(z)] 

is functionally equivalent this:

foo = [] i, num in enumerate(z): # num element in z, index of num     if % 2 == 0:         foo.append(num*8)     else:         foo.append(num*4) 

then user calls sum on result.
answer question?

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edit: explain enumerate

you should used reading documentation on functions, example enumerate. after you've read it, if still don't understand should search stackoverflow. example: a post asking enumerate answer

calling:

for num in z:     = z.index(num)     # stuff 

is functionally same saying:

for i, num in enumerate(z):     # stuff