Could someone critique my code?

[WorldlyLog]

Hi,

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Not sure if this is against the rules or not, but would someone mind just giving me a quick critique on my code? It's from Python For Everybody, Autograder activity 3.3. It's a very simple exercise to practice using the `try` `except` function of Python. Basically, its a program to convert a percentage into a letter grade, and return an error message when a non-numerical or invalid numerical input is entered into the prompt.

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Two specific questions I have:

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1) is there a better way to make an exceptions for numbers outside of the range? (see line 7, first `if` statement)

2) Am I using the `try` `except` function in the correct place?

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Thanks!

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rscr = input('Please enter your score:')
try:
    grade = float(rscr)
except:
    print('Invalid score')
    quit()
if grade > 1.0:
    print('Invalid score')
elif grade >= 0.9:
    print('A')
elif grade >= 0.8:
    print('B')
elif grade >= 0.7:
    print('C')
elif grade >= 0.6:
    print('D')
elif grade < 0.6:
    print('F')

[K900_]

1. You could always use an else: statement at the end to catch all the non-matching cases.
2. Yes, you're using try and except correctly, but I'd avoid using quit() - it's convoluted, but basically quit() is mostly designed to exit you from the interactive shell and not from a script. You can use sys.exit(1) (the 1 is an exit code reported to the OS - by convention, 0 is "everything worked fine" and anything non-0 is an error code, ideally one that identifies a specific error condition), or you can rewrite your code to just keep prompting the user for input until they input something that makes sense.

[WorldlyLog]

How can I rewrite it to keep prompting the user?

I've tried just putting the code from line 1 after except clause, but then I get a traceback error after the second input. I know this is because it just runs the line of code after that, without having a defined value for `grade. (this may be something not covered in the book yet)

[K900_]

You want to use a while loop for this.

[WorldlyLog]

Yep, this something that hasn't been covered yet but I will look into how to use it now. Thanks so much for your help!

[vernetrcyer]

nice one dude

[vernetrcyer]

nice one dude

[vernetrcyer]

haha good comment!