Sometimes I write code like this. Then I delete it and replace it with a for loop, because a loop is just easier to understand. This functional style is what I

Sometimes I write code like this. Then I delete it and replace it with a for loop, because a loop is just easier to understand. This functional style is what I call write only code, because the only person who can understand it is the one who wrote it. Pandas loves this kind of method chaining, and it's one of the chief reasons pandas code is hard to read.