Module 7 - Section 1 - Classes

7.1.6 - Functions and References

Now let's use the reference with a function.

def give_money(person):
    person.money += 100

class Person():
    def __init__(self):
        self.name = ""
        self.money = 0
 
bob = Person()
bob.name = "Bob"
bob.money = 100

give_money(bob)
print(bob.money)

And review it in www.pythontutor.com

ref_funct As you can see in this example the function takes as an argument a person which is a memory address of the object. Think of it as a bank account number. The function uses this copy of the account number to deposit 100 euros. This causes Bob's bank account balance to go up.

Exercise 1

In Thonny's scripting area create a program as follows:

Create a class called Cat with attributes for name, color and weight.
Create a method inside the class called meow.
Create an instance of the cat class, set the attributes, and call the meow method.

Exercise 1 answer

Exercise 2

In Thonny's scripting area create a program as follows:

Create a class called Monster with attributes name and an integer attribute for health.
Create a method called decrease_health that takes in a parameter amount and decreases the health by that much.
Inside that method, print that the animal died if health goes below zero.

Exercise 2 answer