Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Python Object-Oriented Python (retired) Inheritance __str__

Posted by Tristan Gaebler
Tristan Gaebler
6,204 Points

I need help with a code challenge...

I can't see what I'm doing wrong on step 2. I don't think i really understand str. What's it suppose to do? Here's my code

'''from game import Game

class GameScore(Game): pass

def _str(self): return "Player 1: {}; Player 2: {}".format(self.score, self.score)

game_str.py 
from game import Game

class GameScore(Game):
  pass

  def __str_(self):
    return "Player 1: {}; Player 2: {}".format(self.score, self.score)

2 Answers

Jason Anello
Jason Anello
Courses Plus Student 94,592 Points

Hi Tristan,

The str method requires double underscores on both sides.

Also, you have a problem with the arguments you're passing to .format

self.score is a tuple which contains both player scores. You need to be able to access each individual score.

You could access player 1's score like this `self.score[0]

Alternatively, you could simply unpack the tuple with a single asterisk in front. Like this .format(*self.score)

Jason Anello
Jason Anello
Courses Plus Student 94,592 Points

I forgot to answer your other question about what __str__ is supposed to do.

This method would be called for you anytime a string representation of your object is needed and it needs to return a string object.

For example, lets say you wanted to print your object. Your object needs to be converted to a string in order to be printed. So python will call your str method and the string returned from the method is what you will see get printed.

Also, once you start putting code in your class you no longer need the pass statement. This is only needed as a placeholder when your class is empty.

Tristan Gaebler
Tristan Gaebler
6,204 Points

Thanks for the response. The tuple was my problem. I haven't taken python collections yet. I went straight to object oriented programming. Correct me if I'm wrong. A method is a function that belongs to a class?

Jason Anello
Jason Anello
Courses Plus Student 94,592 Points

Yes, the generally accepted terminology is that a function on its own is a function but inside of a class it's called a method.

Gordon Reeder
Gordon Reeder
2,521 Points
Gordon Reeder
Gordon Reeder
2,521 Points

You have a typo on the next to the last line. there needs to be a double underline after str. Like so:

__str__

I'll have to double check (I should know this) but I think str is an attribute not a method. Someone correct me if I'm wrong. Edit: I have been corrected.