Returning lines that differ between two files (Python)

Question

I have two files with tens of thousands of lines each, output1.txt and output2.txt. I want to iterate through both files and return the line (and content) of the lines that differ between the two. They're mostly the same which is why I can't find the differences (filecmp.cmp returns false).

Answer 1

7.4. difflib — Helpers for computing deltas

New in version 2.1.

This module provides classes and functions for comparing sequences. It can be used for example, for comparing files, and can produce difference information in various formats, including HTML and context and unified diffs. For comparing directories and files, see also, the filecmp module.