Instance Methods - Lab

Introduction

In the last lesson, we talked about instance methods -- what are they and how to define them. In this lab, we are going to put our new skills to the test and start writing our own instance methods on our classes.

Objectives

You will be able to:

Define classes and instantiate instances of those classes
Define and call instance methods

Defining Classes and Instance Methods

In this section, define two classes, Driver, Passenger.

In the Driver class, define the instance method greeting that returns the string "Hey, how are you?". Then define the method ask_for_destination, which returns the string "Where would you like to go today?".

In the Passenger class, define the instance method reply_greeting that returns the string "I am doing well! Thanks for picking me up today!". Then define the method in_a_hurry, which returns the string "Punch it! They're on our tail!".

Define these classes and instance methods in the cells below

Remember: as we learned in the previous lesson, we need to define our instance methods with at least one argument (self) in order to call them on an instance object. Don't worry, we will learn more about this argument in a later lesson.

# Define Driver class here

# Define Passenger class here

Instantiate Instances and Practice Using Instance Methods

Great! We've defined our classes and our instance methods. Now, in this section we are going to actually use them!

Start by instantiating two drivers and two passengers. Assign the drivers to the variables daniel and meryl and assign the passengers to niky and terrance.

daniel = None # driver
meryl = None # driver
niky = None # passenger
terrance = None # passenger

Alright, we have our passengers and drivers! Now we need to put those instance methods to use. Try them out and assign the return values to the variables below. Let's have daniel greet his passenger, who is going to be niky. Assign the greeting to the variable, polite_greeting. Have niky respond by calling in_a_hurry, and assign the return value to the variable, no_time_to_talk.

polite_greeting = None
print(polite_greeting)

no_time_to_talk = None
print(no_time_to_talk)

Extra Practice

Now, let's have some extra practice creating classes, instantiating objects, and using instance methods.

In the cells below, you'll create three different classes that represent animals in a zoo--lions, tigers, and elephants. Each animal should have a method, speak, which returns a string containing the sound they make (feel free have some fun with this--we don't know how to spell the sound an elephant makes any better than you do!).

# create Lion class

# create Tiger class

# create Elephant class

Now, in the cell below, create an instance of each animal.

simba = None
tony = None
dumbo = None

Now, append each of them into the list zoo in the cell below.

zoo = None

Now, loop through the zoo list and call print out the .speak() method for every animal in the zoo.

Summary

In this lab, we practiced defining classes and instance methods. We then instantiated instances of our classes and used them to practice calling our instance methods.