Python line continuation

PEP 8 is Python's Bible when it comes to style, but it deliberately avoids certain kinds of assertions about how to write code while suggesting some only in examples. One area in which I feel it is too vague is line-continuation. In this article, I'll try to outline the reasons that one wants to continue lines and how one should deal with that. This is partly a matter of preference, but most of the rationales I present will come along with the practical reasons that this choices make sense.

Let's start with the simplest case. You have a line where a simple function call extends past the end of the normal boundary (79 characters per PEP 8, though I find myself trying to stay below that for historical reasons relating to specific editors, formatters and printing systems):

do_the_first_things_first(thefirstthing, thesecondthing, thelastofthethings, reasons=None)

There are many ways that would work. Here's one:

do_the_first_things_first(thefirstthing,
                          thesecondthing,
                          thelastofthethings,
                          reasons=None)