Well, although I never used pandas and never will, if that's about
artworks, that's mine.
Obviously, you need to iterate columns and sum values returned by the
snippet you provided. A quick search tells us to use colums property.
So, it might look like this:
na_sum =
For a python class I am taking..
In this challenge, you'll be working with a DataFrame that contains data
about artworks, and it contains many missing values.
Your task is to create a variable called na_sum that contains the total
number of missing values in the DataFrame. When that's completed,
