So far we’ve covered what a data type actually is in Python. We explored what the functionality of Python’s built-in types (also referred to as primitives) are. We learned how to create our own data types using the
We explored the relationship between a class and an object — we create objects when we instantiate a class, we find the class when we check the
type() of an object. We learned the difference between class variables (the same for all objects of a class) and instance variables (unique for each object).
We learned about how to define an object’s functionality with methods. We created multiple objects from the same class, all with similar functionality, but with different internal data. They all had the same methods, but produced different output because they were different instances.
Take a moment to congratulate yourself, object-oriented programming is a complicated concept.
Define a class
Student this will be our data model at Jan van Eyck High School and Conservatory.
Add a constructor for
Student. Have the constructor take in two parameters: a
name and a
year. Save those two as attributes
Create three instances of the
- Roger van der Weyden, year 10
- Sandro Botticelli, year 12
- Pieter Bruegel the Elder, year 8
Save them into the variables
Grade class, with
minimum_passing as an attribute set to
Grade a constructor. Take in a parameter
score and assign it to
In the body of the constructor for
self.grades as an empty list.
.add_grade() method to
Student that takes a parameter,
.add_grade() should verify that
grade is of type
Grade and if so, add it to the
grade isn’t an instance of
.add_grade() should do nothing.
Create a new
Grade with a score of
100 and add it to
.grades attribute using
Great job! You’ve created two classes and defined their interactions. This is object-oriented programming! From here you could:
- Write a
.is_passing()that returns whether a
Gradehas a passing
- Write a
get_average()that returns the student’s average score.
- Add an instance variable to
Studentthat is a dictionary called
.attendance, with dates as keys and booleans as values that indicate whether the student attended school that day.
- Write your own classes to do whatever logic you want!