Python can't replicate the structure of this JavaScript code:

  fooBaz(x => {
    // multiple lines of logic
  })

In python, you are forced to move the logic away from the point of usage, which means you lose some locality. This loss is sometimes not worth getting a "name" for the logic.

Of course, sometimes it is better to create a named function away from the point of usage, but I don't think that is always the case.