List of Lists: Comparing indexes of all lists inside a master list

Question

I have a list of lists of integers. Such as

RedValues=[R,R1,R2,R3,R4]

R through R4 are all lists of integers.

What I need to do is compare the first value in each sublist and "take" the median value.

Specifically I am rebuilding an image with 9 different images and taking the median red color pixel in each file.

If anyone can be of assistance with this particular problem I appreciate it.

So R[3] compared to R1[3] compared to R2[3] ...and take median.

Thinking about a nested for loop?... for x in RedValues: for x in R: ...?

Answer 1

You can loop over all the 0th elements, then the 1st, then the 2nd... using zip :

for rs in zip(*RedValues):
    m = median(list(rs))