函数调用与回调的区别及无参数回调调用方式咨询

Absolutely! Let's break this down based on the two scenarios you're likely working with:

1. When passing a callback reference to another function/method #

• When you write callback=self.on_goal, you're handing over a reference to the function itself to whatever system expects the callback. That system will then invoke on_goal() without arguments at the right time.
• If you tried callback=self.on_goal() instead, this would immediately run on_goal() right then and there, and pass its return value to the callback parameter. This is almost never what you want for a callback (unless on_goal returns another callable function, which is a more advanced edge case).

2. When you want to directly invoke on_goal() without parameters #

• This is totally straightforward! You can call it the regular way anytime: self.on_goal(). This will execute the function immediately, no callback setup needed.

Quick example to make it concrete: #

class Game:
    def on_goal(self):
        print("Score!")
    
    def register_event(self, trigger_event):
        # Simulate an event triggering later
        trigger_event()

# Using as a callback
my_game = Game()
my_game.register_event(trigger_event=my_game.on_goal)  # Correct: passes function reference, which gets called later

# Regular direct call
my_game.on_goal()  # Directly executes, prints "Score!"

So to sum up: use self.on_goal when you need to pass the function as a callback (so it can be invoked later), and use self.on_goal() when you want to call it immediately the standard way.

内容的提问来源于stack exchange，提问作者Dave 494