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Comment by zepolen | Hacker News Reader

I don't agree with allowing characters to go over 80 - there is rarely a time the code can't be broken down to fit.

80 characters helps a lot since you can count on all code to fit within a certain area - so you can run three side/side text buffers in your text editor, instead of two with lots of useless white space because a few lines might be too long.

Doing a simple overview of the requests library, most of the lines over 80 characters are just laziness such as:

https://github.com/kennethreitz/requests/blob/master/tests/t...

And a few of the actual potential cases for going over 80 characters can still be broken down without losing any readability:

https://github.com/kennethreitz/requests/blob/master/request...

          r.headers['Proxy-Authorization'] = _basic_auth_str(self.username,
                                                             self.password)

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I have lots of classes and method names that are descriptive but also make 80 chars harder to read. In past I've had to sacrifice readibility to follow strict 80 char limit rule it is a bad idea to enforce it. 99% of time you are not doing merges that require you to have 3 side by side buffers. It makes no sense to point this as the main reason to maintain the limit in my opinion. 100 char limit is way more sane, 95% of time 79 is enough for me but for the remaining 5% to enforce it means to actually make it less readable or make more cryptic variable names which is even worse imo..

I like descriptive names too, EvenToThePointOfAbsurdity, but if the 80 char limit is starting to be imposing, it's usually an indication that code should be refactored as it's being indented too much, or one thing is trying to do too many things.

3 side/side buffers is arbitrary, (it would be 2 on a small laptop display) - and maybe that's why I like 80 characters, it lets me develop on any screen without needing more real estate because the files are long.

I mean Angular has iirc 120 characters, and if you take a look at an average source file eg:

https://github.com/angular/angular/blob/master/modules/%40an...

You'll see a ton of white space after 80 characters that is 'wasted' - this also eats up into horizontal real estate of another buffer which in the end means you actually have less information on the screen with >80 characters rather than more.

In all cases - the code in that file could easily be broken into multiple lines and not lose any readability.

> * 3 side/side buffers is arbitrary, (it would be 2 on a small laptop display) *

It's about 1/3 of my 13" 2013 Macbook Air - the other 2/3 is usually a browser.

It's also not even about how much horizontal space there is for any reason - it just scans better if you keep it narrower.

> there is rarely a time the code can't be broken down to fit.

Yes, it can. It also might end up being: a) less readable, b) uglier

Resources are limited so I'd rather devote my efforts to fixing major styling problems rather than a line that goes over 3 characters

Having a hard limit is overblown nitpickness (and even the 1st line of Pep8 warns you against those)

Not to mention how to do line continuation involves different conflicting styles

Find an example in your code base where you had to go over 80 characters.

  find . -name '*.py' | xargs grep -n '^.\{80\}'

and post it here.

You "don't" need to go over 80 chars.

But it's stupid to break a line like this in two

stuff.do_something_funny(abc, def, ghi)

when the limit is reached at the 3rd parameter (or worse, at the parenthesis)

By that reasoning you could almost say 'find an example where you had to go over [insert arbitrary number between 50 and 100 or so]'. If the number if low enough or my screen is wide enough I could fit 4 text editor panes next to each other :] Any code could probably be broken up to match that as well.

Don't get me wrong, I personally think 80 is a fine number and it's what I use myself. But making things like this hard rules for what basically are arbitrary reasons (e.g. depending on screen resolution) doesn't seem right in my book. I'm seriously not even considering doing something about a line if it's 81 characters.

Try this on the python source itself and you'll find a lot of perfectly reasonable examples. One problem is that in a method, your first meaningful indent is actually three (12 spaces in) - two are eaten up in declaration ceremony. In a language with delimiters instead of significant whitespace you could just fiddle with the convention - for instance, you could decide that you're just not going to give up a full indent for toplevel class members. This isn't an option in Python.

> One problem is that in a method, your first meaningful indent is actually three (12 spaces in) - two are eaten up in declaration ceremony.

I think that's just as reasonable as the rest of Python's whitespace usage, since it (hopefully!) causes the programmer to consider whether that ceremony (classes, methods, etc.) is neccessary or just overcomplication.

It's directly comparable to, say, nesting lambdas in lambdas in lambdas; probably not great for readability, etc. It just-so-happens that in Python's OO, that first lambda is called a class and the second is called a method (objects are a poor man's closures, and closures are a poor man's object!)

For all the 'multi-paradigm' talk, it's still mostly an OO language and almost everything non-trivial written in python is structured in classes and methods. So that's 12 spaces with your first real indent. It's not the end of the world (nor do I think it's there to discourage one from using classes and methods) but it makes it easy enough to hit 80 chars to the point where a strict 80 column limit is a little too restrictive.

Not python, but in Java, identifiers can get quite long. e.g.: "localizableRUNTIME_MODELER_PORTNAME_SERVICENAME_NAMESPACE_MISMATCH" is the longest at 66 characters.

As for python, some fancy list comprehensions get rather long rather quickly. Especially if itertools are involved as you izip, etc. Or using useful variable names (i.e. not 'fcnt', 'tcnt') while destructuring as in this example from pyspark/mllib:

(failure_count, test_count) = doctest.testmod(globs=globs, optionflags=doctest.ELLIPSIS)

I adapted your grep to:

  find . -name '*.py' | xargs grep -n '^ *.\{80\}'

So leading indentation doesn't mess with the results.

Leading indentation is very much a part of the results especially in a language like python where the indentation is syntactically significant. You can't just decide to toss it to make a line shorter.

Preventing people making unreadable list comprehensions is exactly the sort of thing the 80 character limit is for ;)

> As for python, some fancy list comprehensions get rather long rather quickly.

Sure, and we all know that indentation in Python is not allowed for list comprehensions.

    class Foo:
        # ...
        def bar():
            # ...
            if baz:
                # ...
                result = [
                    y.strip()[1:14].replace("this", "that")
                    for x in nabla.generate(q, w, y, z)
                    for y in x.something_other()
                    if y.has_property(...)
                ]

But the 80 characters limit includes indentation

i just love that i had never thought of trying to find lines of code of a certain length this way and you probably just wrote it without a second thought.

hn is such a cool place. :)

I was in the camp of "I disagree with 79 character rule" when I started. However, as someone who has written lots of Python for work, I realized that it does make the code look more readable and while I used to do it initially out of compliance with the existing code, I now do it it because I like it.

Does anyone else feel this way? Or I like it because I had to do it and therefore had to like it in the process.

I was the same and of the opinion that this was mostly a relic of the past.

Then I was assigned a project where this was enforced in the test suite and had to religiously follow pep8. It took a while to get used to but after a while the benefits (like fitting into everyone's editor configuration, cleaner list comprehensions etc) became apparent.

Now I'm the one to put flake8 as a part of the test suite in any new python project :)

While 80 characters may be a bit restrictive, there is a need for a hard limit of something.

I've found that in the absence of a hard limit, you all too quickly end up with a codebase riddled with 250+ line monsters forcing you to scroll right and left all over the place just to get the faintest smidgen of an idea of what's going on. It's a maintenance nightmare.

Meanwhile, GitHub won't show lines longer than 132 characters (on Windows) or 123 characters (on the Mac) without scrolling, no matter how wide your screen.

I personally find 100 seems to strike the right balance.

If punch cards were 160 columns wide, we'd all be enforcing that as the maximum line width. It's arbitrary.

I typically go with 'about 1/3 of my screen width' so I can develop in multiple windows without horizontally scrolling. That's a lot more than 80 chars on a 4k screen.

> 80 characters helps a lot [...] so you can run three side/side text buffers in your text editor, instead of two with lots of useless white space because a few lines might be too long.

Add the fact that there still are people who print the code on paper out there.

very dependent on the language imo

C tends to be terse, so easy to imagine things under 80

python (due to lack of decent types/more verbose community) has more of a need for those 80 chars.

I think there's likely a per-project line limit that "makes sense".

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