function in a class python code example

Example 1: python classes

class Box(object): #(object) ending not required
  def __init__(self, color, width, height): # Constructor: These parameters will be used upon class calling(Except self)
    self.color = color # self refers to global variables that can only be used throughout the class
    self.width = width
    self.height = height
    self.area = width * height
  def writeAboutBox(self): # self is almost always required for a function in a class, unless you don't want to use any of the global class variables
    print(f"I'm a box with the area of {self.area}, and a color of: {self.color}!")

greenSquare = Box("green", 10, 10) #Creates new square
greenSquare.writeAboutBox() # Calls writeAboutBox function of greenSquare object

Example 2: python classes

class Student:
  def __init__(self, id, name, age):
    self.name = name
    self.id = id
    self.age = age
  
  def greet(self):
    print(f"Hello there.\nMy name is {self.name}")
    
  def get_age(self):
    print(f"I am {self.age}")
    
  def __add__(self, other)
  	return Student(
      self.name+" "+other.name,
      self.id + " "+ other.id,
      str(self.age) +" "+str(other.age))
    
p1 = Student(1, "Jay", 19)
p2 = Student(2, "Jean", 22)
p3 = Student(3, "Shanna", 32)
p4 = Student(4, "Kayla", 23)


result = p1+p3

Example 3: class methods in python

from datetime import date

# random Person
class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    @classmethod
    def fromBirthYear(cls, name, birthYear):
        return cls(name, date.today().year - birthYear)

    def display(self):
        print(self.name + "'s age is: " + str(self.age))

person = Person('Adam', 19)
person.display()

person1 = Person.fromBirthYear('John',  1985)
person1.display()