Removed lines happen between existing lines, so using an underscore makes it look like that. Compare: 25 - def foo(): 26 baz() With: 25

Removed lines happen between existing lines, so using an underscore makes it look like that. Compare: 25 - def foo(): 26 baz() With: 25 _ def foo(): 26 baz() (Where there used to be a bar() call before baz().) The first version makes it look like the `def foo():` was somehow removed.