-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Feb 21, 2008, at 12:30 PM, Guido van Rossum wrote:

On Thu, Feb 21, 2008 at 9:15 AM, Barry Warsaw wrote:

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Why should docstrings and comments be limited to 72 characters when code is limited to 79 characters? I ask because there is an ongoing debate at my company about this.

People in your company have too much time on their hands. :-)

C'mon, bike shedding is so much fun! :)

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Personally, I see no justification for it, and further, it's a pita to support automatically because tools like Emacs only have one auto- wrapping variable (fill-column). Emacs doesn't know that it should fill comments and docstrings different than code lines, so you have to do a bunch of manual crud to support these guidelines.

I recommend removing the guideline of 72 characters, and just say everything, code, comments, and docstrings should be no wider than 79 characters.

I'm fine with getting rid of this, but since that originally comes from me, here's my justification. Somehow my Emacs usually defaults to 72 for its fill column. That means that when I reflow text in a block comment or docstring, it'll use this limit. OTOH I don't use anything to automatically fold long code lines: when they start wrapping I manually decide on the best place to break it (and my windows are typically 80 chars wide so I can have several side by side(*)).

I do the same thing sometimes too.

However there are occasions where I manually format docstrings or comments, and then I will again use 79 as the limit.

Yep.

(*) When is Emacs going to fix the bug where it decides to fold a line that's exactly as wide as the window? This 79 business is really silly, and had to impose on people using other editors.

In 50 years, our grandchildren will be writing code with brain implants and displays burned right into their retina, and they'll / still/ be subject to 79 characters. I laugh every time I think that they'll have no idea why it is, but they'll still be unable to change it. :) - -Barry -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (Darwin) iQCVAwUBR79gjHEjvBPtnXfVAQLn/AQApsNQ7KvoBM6wJgKUDHkS97Sd0qTYeRCy qjFQE/hUtAGebqic3fcAEP3ASPp12fOnBpOWOxm0aQURoDdTi+ClTsXp6v/1aztf 9yC1xT3BH022Te82d3vLgRhixxregHZ+5i8ravb3Tb/xdUa3gouql+DyJw8tEAek MGMdcrqoEfE= =FiB+ -----END PGP SIGNATURE-----

Barry Warsaw wrote:

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On Feb 21, 2008, at 12:33 PM, Ron Adam wrote:

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Barry Warsaw wrote:

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Why should docstrings and comments be limited to 72 characters when code is limited to 79 characters? I ask because there is an ongoing debate at my company about this. I'm not sure if this is the main reason, but when using pydoc to view docstrings, the 72 character width allows for the added indent in class and method sections.

Interesting. Maybe because I almost always put doctests in separate files, I don't run into this too much. Having an indent of 4 for doctest code never really bothers me too much.

I think the 72 character limit refers to the length of the doc string, not the length of the line. Pydoc, ie...the help() function, strips leading white space off and then adds it's own margin, 4 characters for function doc strings, and 8 characters with a vertical bar for class method doc strings. Longer than 72 character doc strings in class methods wrap and break up the output of the help function. Ron

Why not just skip the specifics except to say < 80 characters for all lines? Don't mention 72, 79 or any other number than 80: Maximum Line Length There are still many devices around that are limited to 80 character lines; plus, limiting windows to 80 characters makes it possible to have several windows side-by-side. The default wrapping on such devices disrupts the visual structure of the code, making it more difficult to understand. Therefore, please limit all lines to less than 80 characters. ... Skip

And this is then compounded if you then proceed to diff those diff outputs. Maybe we should just use vertical spacing?

-----Original Message----- From: python-dev-bounces+kristjan=ccpgames.com@python.org [mailto:python-dev-bounces+kristjan=ccpgames.com@python.org] On Behalf Of Amaury Forgeot d'Arc Sent: Friday, February 22, 2008 08:01 To: Skip Montanaro Cc: python-dev Dev Subject: Re: [Python-Dev] [Python-checkins] r60919 - peps/trunk/pep- 0008.txt

Skip Montanaro wrote:

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Why not just skip the specifics except to say < 80 characters for all lines? Don't mention 72, 79 or any other number than 80:

I often run "svn diff" in a console limited to 80 characters. Because of the leading "+", lines longer than 78 wrap, and the output is more difficult to read.

On Fri, Feb 22, 2008 at 10:12:16AM -0600, skip@pobox.com wrote:

I use "svn annotate" from time-to-time which adds an even wider margin to the left. In those situations I either grin and bear it or stretch my window enough to view it without wrapping.

svn blame | less -S Oleg. -- Oleg Broytmann http://phd.pp.ru/ phd@phd.pp.ru Programmers don't die, they just GOSUB without RETURN.

On Fri, Feb 22, 2008 at 8:20 AM, Aahz wrote:

On Fri, Feb 22, 2008, skip@pobox.com wrote:

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>> Why not just skip the specifics except to say < 80 characters for all >> lines? Don't mention 72, 79 or any other number than 80:

Amaury> I often run "svn diff" in a console limited to 80 characters. Amaury> Because of the leading "+", lines longer than 78 wrap, and the Amaury> output is more difficult to read.

There will always be certain cases which present probems. I use "svn annotate" from time-to-time which adds an even wider margin to the left. In those situations I either grin and bear it or stretch my window enough to view it without wrapping.

Yes, but svn/cvs diff is a particularly common use case. I agree with Amaury.

-1. There's just no way that 78 is enforceable. At Google, sticking to 80 is a continuous battle, and we use 2-space indents! -- --Guido van Rossum (home page: http://www.python.org/~guido/)

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Feb 22, 2008, at 11:20 AM, Aahz wrote:

On Fri, Feb 22, 2008, skip@pobox.com wrote:

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Why not just skip the specifics except to say < 80 characters for all lines? Don't mention 72, 79 or any other number than 80:

Amaury> I often run "svn diff" in a console limited to 80 characters. Amaury> Because of the leading "+", lines longer than 78 wrap, and the Amaury> output is more difficult to read.

There will always be certain cases which present probems. I use "svn annotate" from time-to-time which adds an even wider margin to the left. In those situations I either grin and bear it or stretch my window enough to view it without wrapping.

Yes, but svn/cvs diff is a particularly common use case. I agree with Amaury.

My main concern is that we have only one line length limit for everything. If we want that to be 78 or 72 or whatever, okay (though I still think 79 works well :) but I don't see much point in there being more than one limit. - -Barry -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (Darwin) iQCVAwUBR79g/HEjvBPtnXfVAQJCCQP/Qd7nWrSC3Wm6Y4+dPgv0ls1Td3ZTuf7n ZzE6cIiV0h2tgKsS+olRHE2e/ttKNVRask2FPrhUClj4eXG6k3bVU/KsH9JR4wjH Ha1ayDb74ZHqqdSZKrKCcsak5fismBv2Vsn8aDI3eslzFVEd0FF1dU+qQYf/m3je 2gjt9Fx6wYU= =6WAr -----END PGP SIGNATURE-----