ETA: thinking back on it, several years ago I switched from 120 characters to 80 specifically because of this. I don’t have a car, so I read a lot of code on my phone while taking public transit.
I'm surprised reading on a phone is common. Not at all something I would want to do. I'm assuming largely read only there?
Makes me curious if the CWEB idea of styling specifically for reading has extra merit in that flow?
I do not want to type / create on my phone though, certainly not code, or even sign up for stuff / submit / do applications on phone. Makes me a rarity though.
In seriousness, apologies on the confusion.
Yes, aithrowawaycomm's claim about line lengths are supported by many, many different sources who recommend a 50 to 80 character line length.
https://duckduckgo.com/?q=reading+optimal+line+length
IMHO, 80 characters is too narrow, especially with Python, for most coding tasks so I settle more around 100 (+-20) characters. PEP-8 says up to 99 characters is okay.
Shading lines can also improve readability (this is known; the rest of this comment is speculation). It's probably not enough to simply alternating between e.g. white and off-white background, unlike for tables. More likely an alternation between 3 or 4 subtly-different colors is best; maybe these can form a pattern across additional lines (e.g. 121312321). If the difference isn't subtle enough, editing will suffer whenever you break the line count, but for reference only the human eye is pretty good at aligning subtle things. Maybe even an outright paper-texture background image? (This is more often a gimmick, but it can be useful.)
You can't have it both ways though - support hard line limits because the mere discomfort of long lines is insufficent to convince the programmer to refactor to something clearer, and then argue that the mere discomfort of the line limit including indentation should convince the programmer to refactor deeply nested code into something simpler. Which is it? Do we want to force limits with say a linter (80 characters of width max, 5 levels of nesting max) or let the programmer choose based on comfort?
I've had to implement things like an arbitrary-JSON formatter. Setting a fixed width including indentation doesn't work - there would always be (deeply nested) values you simply cannot print according to the rules (excluding, of course, strings which have their own difficulty). I kinda feel 80 characters excluding indentation works out ok in practice in a variety of settings.
> especially with Python