How to Pair Every Username with All Passwords Using Simple Python Loops

Introduction

Hello, I am Pipí. Recently a member of the Python strongest champion group asked a data‑processing question involving two files: one with usernames and one with passwords.

Problem Description

The task is to try every username with every password. The original idea was to first test each username against all passwords and then each password against all usernames, but in fact only the first step is needed.

Solution

A straightforward solution uses a double for loop without worrying about efficiency. The following code demonstrates the approach:

pw = [1,2,3,4,5]
user = ['a','b','c']
for i in user:
    for j in pw:
        print(i, j)

Result

Running the script prints every combination of usernames and passwords, and it works even when the two files have different numbers of lines (e.g., 7,000+ passwords and 8,000+ usernames). The output image below shows the complete traversal.

Conclusion

The article provides a clear Python implementation for the described data‑processing problem, helping readers quickly solve similar tasks.