Book
Module 7 - Section 1 - Classes
Module 7 - Section 1 - Classes
Completion requirements
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After the completion of this module the students will be able to:
- identify a class inside Python code
- present the necessary parts for constructing a class
- create code to construct a simple class
- create and use methods in a class
- distinguish the references from the objects of a class
- rewrite the classes code to implement constructors
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
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 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.