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Python Python Basics (2015) Number Game App Squared

Amos Baynes
Amos Baynes
2,294 Points

I've tried a few variations on this problem, but I keep getting this error: TypeError: can't multiply sequence by non-in

I thought the except TypeError: was supposed to catch this error, but it's still throwing it.

squared.py
# EXAMPLES
# squared(5) would return 25
# squared("2") would return 4
# squared("tim") would return "timtimtim"

def squared(num):
    try:
        int(num)
    except TypeError:
        return num * len(num)
    else:
        return num * num

2 Answers

Jennifer Nordell
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STAFF
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

Hi there! The type error is actually being produced from your else clause. Remember, the int method to convert to an integer can accept either a number or a string. You should be checking for a ValueError here.

In your try part, you have int(num). Imagine for a minute that we send in "27" as a string. That is a string that can be converted to an integer, and thus neither the TypeError nor the ValueError will be triggered and it will hit the else clause. At that point, you then try to multiply the string 27 by the string 27 which can't be done. This is where you're getting the TypeError from. To fix this, in your try block you need to overwrite the current value of num with the num after it's converted to an integer. That way, when your else clause is hit, it will be an integer times an integer.

Hope this helps, but let me know if you're still stuck! :sparkles:

Amos Baynes
Amos Baynes
2,294 Points

Thanks for the quick reply, Jennifer. I'm not clear what you mean by "overwrite the current value of num with the num after it's converted to an integer."

Jennifer Nordell
seal-mask
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

Hi again! A quick hint: num = int(num).

Again, int can take either a string or a number. The string "42" can be converted to an integer. The string "Treehouse is awesome" can not be converted to an integer. And this is where we get a ValueError. The type is correct (a string or integer), but the value is such that it still can't be done.

So assuming we sent in the value "42" as a string, you're trying the int("42") essentially. But the results of that aren't saved anywhere if it was successful. At this point, the value of num will still be the string "42". The line I gave above says take whatever num was before and overwrite it with the integer version of that string if possible.

Amos Baynes
Amos Baynes
2,294 Points

Got it! Thanks a lot for your help!