Password Breaker

Attached will be the rubric my task I have chosen is:

I am writing a python program to access my schools linux server using python. logging on as myself then executing  ypcat passwrd | awk -F “:” ‘print $1’ > users_on.txt  . Everything must be in in one py file.
My train of though it using python to access Putty, log in as my self run the command above to get the users then use a password breaker that I will provide (that I think I made effectively ) to try all 8 (maybe 9) digit numerical passwords if successful increase a counter by 1 and save that username and password to a file.