$24.$ Overview of Exercise $5$

In this exercise, you will implement a function using your choice of if statement, if$-$else statement, or if$-$elif statement. Unlike previous exercises, we will not give you explicit guidance on how to implement this function. You should use your knowledge of Python to design the function on your own.

In the directory exercise$5$ there are two files: func.py and test.py$.$ The file func.py is a module with a function stub for valid$\_$format. You are to implement this function as specified. The file test.py is a fully completed test script to help you as you work on this function. Remember, to run a test script, you run it as a Python application: