What is self

self is a reference to the current instance of the class.

It is used to access variables that belongs to the class.

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

It does not have to be named self, you can call it anything, but it has to be the first parameter of any function in the class.

class Player:
  def __init__(hello, name):
    hello.name = name 
  
  def print_player_name(hello):
    print(hello.name)

player = Player("John")
player.print_player_name() # John