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Python Object-Oriented Python Dice Roller Project Breakdown

Anwar Rizalman
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Anwar Rizalman
Python Development Techdegree Graduate 33,620 Points
Posted by Anwar Rizalman
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Anwar Rizalman
Python Development Techdegree Graduate 33,620 Points

Why not use the try block when checking for errors?

class Die():
    def __init__(self, sides=2, value=0):
        if not sides >= 2:
            raise ValueError("Must have at least 2 sides")
        if not isinstance(sides, int):
            raise ValueError("Sides must be a whole number")

Is there any reason why this style of code was used instead of the try block?

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,457 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points

Good question. A try block is used primarily to detected errors and then handle them without causing the program to halt. In this case, there is no desire to continue so an immediate error is raised.

Post back if you have more questions. Good luck!!

Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points

The best place to use a try block would be surrounding the call to the Die function. Perhaps in the code that asks the user for the sides. Your usage may not have user input, only coder usage. In this case calling with a bad value should definitely raise the error so the code may be fixed.

The Die function does what it can with the arguments given and throws errors on bad input since it doesn’t know how to get better input.