When you have a series with litegogals, you just want to see t theirpo ons of their numbers as a whole. And that usually doesn't include the nul values. So you have to call is null and anchain it with some so that yo get do you learn the number of nats in that column? But you can do it efficiently with value counts with setting,. By setting dropan to falls, which includes the proportions of the null vallues as well. Al again, against the whole data set, not looping only at one column at a time.