Link: https://www.youtube.com/watch?v=MjHpMCIvwsY

python decorator snippet

• What does def add(a, b) do?
  • Define a function object, assign that to the variable/name add
• When creating a decorated function, this involves 3 Callables.

      @mydeco
      def add(a, b):
          return a + b
  
      # This gets translated to ...
      def add(a, b):
          return a + b
      add = mydeco(add)
  
      # 3 Callables
      # * mydeco - callable, receives `add`
      # * Original decorated function `add`, receives whatever arguments it receives
      # * Result of mydeco(add). What's returned here is also a callable
  

• When I call a decorated function, e.g., add, I'm not actually calling add, but whatever calling my decorator mydeco returned.

def mydeco(fn) -> Callable[...]: # <-- Runs only during decoration - once

    # vv Runs every time we call the decorated function vv
    def wrapper(*args, **kargs): # <-- *args, **kargs to accomodate any function arguments
        print(f"I'm just printing the function .... {fn.__name__}")

    # return the callable wrapper...
    return wrapper