It was not a lot of lecture, but I finally finished the python intensive course.

Below are a few things I would like to check again.

Class

1. __init__
   • If __init__ method is used in class, the corresponding method will run when an instance is created.

     •  class CookieFrame():
        def __init__(self, name):
        print(f"The name of the created cookie is {name}")
        self.name = name
       
        cookie1 = CookieFrame("cookie1") # The name of the created cookie is cokkie1
        cookie2 = CookieFrame("cookie2") # The name of the created cookie is cokkie2
       

2. inheriting
   • Class inheritance in python is a function that allows you to import and use features such as variables and methods declared in other classes when creating a class.
   • At this time, the inheriting class is called parents or super class, and inherited class is called child or sub class.

     •  class Monster():
            def __init__(self, hp):
                self.hp = hp
                       
            def attack(self, damage):
                self.hp -= damage
       
            def status_check(self):
                print(f"monster's hp : {self.hp}")
                       
        class FireMonster(Monster):
            def __init__(self, hp):
                self.attribute = "fire"
                # super() allows you to use the parent class's code as-is.
                # The code is the same as executing code self.hp = hp.
                super().__init__(hp)
                   
            # Override the status_check method that exists in the parent class.
            def status_check(self):
                print(f"fire monster's hp : {self.hp}")
                       
        class IceMonster(Monster):
            def __init__(self, hp):
                self.attribute = "ice"
                super().__init__(hp)
                   
            def status_check(self):
                print(f"ice monster's hp : {self.hp}")
                       
        fire_monster = FireMonster(hp=100)
        fire_monster.attack(20)
        fire_monster.status_check()
       
        ice_monster = IceMonster(hp=200)
        ice_monster.attack(50)
        ice_monster.status_check()
       

   • Always use child classes to avoid errors when using classes already created by others.

Decorator

1. Description
   • Decorators are written in the form of @decorator using ‘@’ on top of the declared function, and when the function is executed, the code declared in the decorator is executed as well.
2. Example

   •  # Finding the Execution Time of a Specific Function
      import time
      import random
     
      def time_checker(func):
          def wrapper():
              # Stores the time when the function runs.
              start_time = time.time()
     
              # Running the function
              func()
     
              # When the function runs at the hour after it exits, subtract the time to get the running time.
              executed_time = time.time() - start_time
     
              # Outputs the execution time to 5 decimal places only.
              print(f"{func.__name__} function execution time : {executed_time:.05f}s")
     
          return wrapper
     
      @time_checker
      def main():
          time.sleep(random.randint(1, 10) / 10)
     
      for i in range(10):
          main()
     
      # result output
      """
      main function execution time : 0.80095s
      main function execution time : 0.90009s
      main function execution time : 1.00027s
      main function execution time : 0.20020s
      main function execution time : 0.90011s
      main function execution time : 0.60041s
      main function execution time : 0.30027s
      main function execution time : 0.40024s
      main function execution time : 0.10026s
      main function execution time : 0.50032s
      """
     

   • In addition, you can create a function by inserting an argument into it, so if you use this decorator, you can create an infinite number of functions.

I haven’t started the personal assignment I mentioned last time, but I finished the class today and can proceed properly from tomorrow.