why we use def in oop python code example

Example: python how to use oop

#Object oriented programming is when you create your own custom class.
#One reason you should do this is that is saves you time.
#Another reason is it makes calling certain functions easier with tkinter

class Dog:
  #init creates certain parameters that allow you to define information quickly.
  def __init__(self, name):
    self.name = name
    
  def get_name(self):
	return self.name
    
if __name__ == "__main__":
  d = Dog(str(input("name your dog: "))
  print(d.get_name())