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Python

Posted by Scott Simontacchi
Scott Simontacchi
2,071 Points

Using get_next_monster() before we have defined it

Why is it that we can call get_next_monster() before we have defined it? In the video, you write:

self.monster = self.get_next_monster()

def get_next_monster(self):
...

I would have thought the method would need to be written before it can be used. Thanks for the clarification!

All the best, Scott

2 Answers

Steven Parker
Steven Parker
243,656 Points
Steven Parker
Steven Parker
243,656 Points

You forgot to provide a link to the course video, or the complete context for your code snippet.

But I'd bet that the function is not being used (as in invoked) before it is defined. That top line is probably part of another definition, so it won't actually be executed until the function it is being defined in is itself invoked.

Steven Parker
Steven Parker
243,656 Points
Steven Parker
Steven Parker
243,656 Points

:point_right: No matter what order they appear in the file, all the functions have been defined when the call to Game is performed at the end. So at that point, everything is available.

You would have trouble if you tried to call Game at the top of the file.

Scott Simontacchi
Scott Simontacchi
2,071 Points
Scott Simontacchi
Scott Simontacchi
2,071 Points

Your insight is impressive, that is exactly what is happening! See below:

class Game:
  def setup(self):
    self.player = Character()
    self.monsters = [
      Goblin(),
      Troll(),
      Dragon()
    ]
    self.monster = self.get_next_monster()

  def get_next_monster(self):
    try:
      return self.monsters.pop(0)
    except IndexError:
      return None

I'm still a bit confused about it though... At the end of the file we call Game() to start the program and, if it runs from top to bottom, shouldn't self.monster need to get self.get_next_monster() before it knows what it is? Why doesn't it matter?

Thanks so much for your help!

Scott

Steven Parker
Steven Parker
243,656 Points
Steven Parker
Steven Parker
243,656 Points

See comment attached to my answer :arrow_heading_up: