Introduction to Pandas: wrong answer in quiz


This question has wrong answer. The answer’s variable name doesn’t follow variable rules so that it will throw SyntaxError. So the answer’s variable name must concatenate with ‘_’, not ‘-’. Or second’s answer could be correct answer if the DataFrame is assign as ‘column’. Plz check it out :slight_smile:

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Yes. I believe you are correct. For the ‘Correct’ answer to actually be correct is should read:

office-supply-store['remaining-inventory'] = office-supply-store['initial-inventory'] - office-supply-store['number-sold']

No clue why they decided to use hyphens in all of the names here. Bizarre!
Would either @patrickd314, @thepitycoder or @chuckwondo care to weigh in before I report this as a bug?


I think your proposed correction is correct… The column names, e.g. number-sold aren’t valid identifiers so you would (I think) need to use the df.[colname] form…

office_supply_store['remaining-inventory'] = office_supply_store['initial-inventory'] - office_supply_store['number-sold']

Thanks! I guess it’s what you mean :slight_smile:
I hope to codecademy will fix it soon

Yes it is. As you mentioned, df[columnName] form is correct :slight_smile:

Actually the data frame itself having hyphens in the name seems to work, but the hyphens in the column names require using the df['column-name'] syntax to reference them. Again, I don’t know why they would have used hyphens. It likely is a typo.


I see. I hope they fix it soon. Thanks! :rofl:

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I submitted a bug report directly to the Codecademy Team. We’ll see what happens.

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