variables in classes 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: call instance class python

# define class
class example:
# define __call__ function
   def __call__(self):
       print("It worked!")
# create instance
g = example()
# when attempting to call instance of class it will call the __class method
g()
# prints It worked!

Example 3: class variable in python

# Class variables refer to variables that are made within a class.
# It is generated when you define the class.
# It's shared with all the instance of that class.
# Example:

class some_variable_holder(object):
    
    var = "This variable is created inside the class some_variable_holder()."
    
    def somefunc(self):
        print("Random function ran.")

thing = some_variable_holder()
another_thing = some_variable_holder()

# Both does the same thing because the same variable has been passed on from the class.
thing.var
another_thing.var