compare 2 lists of integers

Question

I have 2 txt files like this:

fileA:      fileB:
0           0   
5           0 
0           80
20          10 
600         34

I need to compare the numbers in these 2 lists respecting the position in the list. I need to generate an output file with the comparison for each of the lines like:

Output:
E
A
B
A
A

I have tried something like:

lineA = [lineb.rstrip('\n') for lineb in open("fileA.txt")]
lineB = [lineb.rstrip('\n') for lineb in open("fileB.txt")]
for i in lineA:
    for u in lineB:
        if lineA[i] > lineB[i]:
           print("A")
        elif lineA[i] < lineB[i]:
           print("B")
        elif lineA[i] == lineB[i]:
           print("E")

but the loop is not able to work properly. I've tried also to convert first the list in integers ( in case they are not recognized ad int) like:

for w in range(0, len(lineA)):
    lineA[w] = int(lineA[w])
    print(str(lineA))

BUT I CAN'T SOLVE THE PROBLEM...

Answer 1

You can use zip to loop through the two lists in parallel:

# use `with` to automatically close the files after reading
with open("fileA.txt") as file_a, open("fileB.txt") as file_b:
    # use `int` in the list comprehension
    # and, use `.rstrip()` if you just want to remove whitespace
    lineA = [int(line.rstrip()) for line in file_a]
    lineB = [int(line.rstrip()) for line in file_b]

for i, u in zip(lineA, lineB):
    if i > u:
       print("A")
    elif i < u:
       print("B")
    else:
       print("E")