PEP 8 : Maximum line Length :

[Rustom Mody]

On Friday, May 16, 2014 3:51:27 AM UTC+5:30, Terry Reedy wrote:
> On 5/15/2014 9:58 AM, Rustom Mody wrote:
> 
> 
> > As far as I can see the votaries of the mystical 79 have yet to explain
> > how/where it appeared from
> 
> 
> 
> As has been explained before, and is implied in the PEP, 79 = 80 - 1.
> 80 chars - 1 character width cursor leaves 79 non-cursor characters. 
> When <enter> is hit, the cursor replaced with \n. So you can think of 79 
> as 79 visible + \n = 80.
> 
> 
> 
> PEP 8 says "The limits are chosen to avoid wrapping in editors with the 
> window width set to 80," and goes on about dynamic wrapping or not. To 
> put is another way, all 80 char terminals work with 79 visible chars. 
> Some but not all work with 80 visible, and some work with 80 on all 
> lines except the last.
> 
> 
> 
> I admit that this would have been clearer when most everyone reading it 
> would have had some experience with 80 char sceens (including DOS). 
> Still, did you really not notice that 79 = 80 - 1?

The claim being made is that 79/80 is a fundamental, cognitive limit and has 
no relation to technological changes.