Append text file in python

Question

I want to write a code which appends a file as follows:

Input file contents are:

a,b
c,d

I have another file with contents:

2
4

The contents in output file should be:

a,b,2
c,d,4 

I am not able to write a code for this. Can anyone help me out with this please!!

Answer 1

Even if I agree with the first comment, I like internet points.

First, open and read the lines of all files and remove all trailing newline characters

a = [i.strip("\n") for i in open("fileA.txt").readlines()]
b = [i.strip("\n") for i in open("fileb.txt").readlines()]

Add the content from each line of b to a

for i in range(len(a)):
    a[i] = a[i] + "," + b[i]

Finnaly write to a third file

c = open("fileC.txt", "w") # With write permissions
for i in a:
    c.write(i)

Close (and save) all files

a.close()
b.close()
c.close()