python - Adding calculated column in Pandas

Question

I have a dataframe with 10 columns. I want to add a new column 'age_bmi' which should be a calculated column multiplying 'age' * 'bmi'. age is an INT, bmi is a FLOAT.

That then creates the new dataframe with 11 columns.

Something I am doing isn't quite right. I think it's a syntax issue. Any ideas?

Thanks

df2['age_bmi'] = df(['age'] * ['bmi'])
print(df2)

Answer 1

try df2['age_bmi'] = df.age * df.bmi.

You're trying to call the dataframe as a function, when you need to get the values of the columns, which you can access by key like a dictionary or by property if it's a lowercase name with no spaces that doesn't match a built-in DataFrame method.

Someone linked this in a comment the other day and it's pretty awesome. I recommend giving it a watch, even if you don't do the exercises: https://www.youtube.com/watch?v=5JnMutdy6Fw