Lesson: Methods

Learning Objectives

Students will be able to...

• Define and identify: method, __str__, __add__, operator overloading
• Create a class with an init method
• Understand and use the self
• Instantiate a class with an argument

Materials/Preparation

• Do Now
• Lab
• Associated Reading - section 6.3 of Book
• Read through the handout, lesson, and lab so that you are familiar with the requirements and can assist students

Pacing Guide

Instructor's Note

1. Do Now
   • Display the Do Now on the board.
2. Lesson
   • Discuss Do Now
     • method: functions inside a class. First argument is always self. What is a method we have seen? (init)
     • Ask students how they would distinguish between the two time variable
     • __string__: Need a method called __str__. This will get called when you print an object. It returns a string
       • Have the students practice writing __str__ for time for 5 minutes
       • Have a student write up their string method on the board.
     • __add__: add is another method that gets called when the plus sign is used. Takes in another time object and returns a time object that is the sum of both
       • overwriting add is called operator overloading because you are re-writing the code used to make the + work
       • work together with students to come up with the add time algorithm
3. Lab
   • Have students finish up the time adding method
   • Have students work on manga too lab from book
4. Debrief
   • Go over students' questions. Ask what an instance is versus an object vs a class. Ask difference between method and attribute.