The new match Boss Statement

Here is the program we built in class.

n = input("Enter an integer: ")
n = int(n)
match n:
    case 1:
        print("n = 1")
    case 2:
        print("n = 2")
    case 3:
        print("n = 3")
    case 4|5|6:             #here we are "orring
        print("mighty big number")
    case _:                 #this is the default.
        print("Try a number 1-6, Bub.")

Modules and the Python Standard Library

What is a module? It's a Python program. Many modules have no main routine. They are collections of related functions residing in a file. We have seen this with the math module.

Where can I see all of the Python modules? They can be found in the Global Module Index in the Python documentation. These modules can do a vast array of tasks for you. You should look up the math module and see its contents.

We begin by learning about the module sys and its object sys.argv, which returns a list of strings that the user types after typing "python". This is the program mystery.py that we created.

import sys
print(sys.argv)
print(type(sys.argv))

Running this reveals that sys.argv is a list of strings. Run this by typing several items after python mystery.py These items are called command-line arguments They allow you to inject information into a program right at the beginnning so that no input statement is needed.

Can I make my own module? Yes. We will see how to do this the smart way.