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by driggs 523 days ago

Anyone who can't see past Python's indentation-based syntax is a person who doesn't understand Python.

(Both literally and figuratively!)

When "significant whitespace" is at the top of someone's complaints about Python, I'm immediately done hearing about their superficial criticism of the language.

8 comments

mkl 523 days ago

Agreed. I find such complaints very strange, as most people already follow Python-like indentation rules quite strictly in most other languages, but need to add delimiters as well. Indentation is the clearest indication of code structure, so when it's not significant it still looks significant, leading to bugs like:

  if(condition)
      do_thing1();
      do_thing2(); //not in the if!
  do_thing3();

dariusj18 522 days ago

My problem with indentation as significant is when I paste a chunk of code inside some chunk that is indented differently. Some may say that a good text editor will deal with that for you, but it's rarely been the case for me. The most is when the code is longer than my screen height and I have to scroll down and figure out where the pasted chunk ends and indentation it all who knows how many times without scrolling back up to the top of the chunk.

smitelli 522 days ago

Speaking only as myself, usually when I find myself having the scrolling problem the function/method is crying out to be broken down and refactored anyway.

wwfn 523 days ago

Literate programming tools that weave/tangle code and documentation don't play well with significant whitespace. Not a problem for me, but I think it's on a valid line of complaints.

Jtsummers 522 days ago

Which ones? Org mode's babel works fine with it. If you do something like this (loose, not precise babel syntax):

  <<body>>=
    if 1 == 1:
        print('1 == 1, shocking!')

  <<function>>=
    def foo():
      <<body>>

It will generate properly indented code when tangled as in:

  def foo():
    if 1 == 1
        print('1 == 1, shocking!')

Note that it puts in precisely two extra spaces for each line in the tangled `body`, which is the amount used in the block named `function` where it references `body`. If you used 4 spaces of indentation, it would use 4 in the tangled output. I've also used noweb and don't recall this being an issue, however that was not with Python so it's possible I just didn't notice a problem with it.

wwfn 521 days ago

I stand corrected! I'm guessing my own bad formatting lead me astray at some point. I tried to come up with a pathological example that'd break with noweb just now and had no luck.

driggs 522 days ago

I very strongly disagree. The most successful implementation of literate programming is the Jupyter Notebook, formerly called iPython Notebook. Even when you write it as raw markdown, there's no issue mixing documentation with triple-backtick code blocks.

Maybe you're thinking of mixing Python with HTML? Python based HTML templating can be ugly, and the significant indentation of Python is a very poor mix for replacing Javascript in whitespace-agnostic HTML.

wwfn 521 days ago

I thought tools like jupyter and rmarkdown are better described as narratives[0] (lab notebooks and report generators) separate from and almost antagonistic to literate programming[1]. At least as I've been exposed to them, notebooks don't easily facilitate code reuse -- libraries aren't written in notebooks but could be written with literate programming tools.

[0]: https://khinsen.wordpress.com/2015/09/03/beyond-jupyter-what... [1]: http://www.literateprogramming.com/

tommiegannert 522 days ago

> there's no issue mixing documentation with triple-backtick code blocks.

Your argument became: By adding delimiters, even Python can play well with other languages. /s

nomel 522 days ago

Technically comments are considered blank lines, so indentation can be arbitrary. This is against PEP8/linters, but it's not a formatting error.

Triple quoted docstrings just require that the initial marker (""" or ''') is indented properly (since they are not considered blank lines). All contained text, and the closing marker, can be at any indentation level. This is the cleanest way to include a page of free form documentation, mid anywhere.

dgfitz 522 days ago

I agree. I think it’s only an issue because we as a collective didn’t sort out a tabs-vs-spaces debate and new people to the language struggle with that bit.

Yizahi 522 days ago

The problem is that in the year 2024 there are no real technical arguments against tabs. I suspect very few people saw any tab mangling system ever in their lives or even at all. We are like monkeys from the anecdote about bananas and waterhose. All the population has been replaced multiple times and waterhosse is long dead, but we are still afraid to touch the forbidden fruit.

diggan 522 days ago

> The problem is that in the year 2024 there are no real technical arguments against tabs.

Since you added "real" in there, no argument really matters. But regardless, it's funny you say that, as Python current style guide (https://peps.python.org/pep-0008/) outlines 4 spaces as the one and only correct way of writing Python code.

Yizahi 522 days ago

The emphasis was on the word technical. The only technical argument I've ever heard against using tabs for indentation only, was that some software text editor a long time ago mangled tabs. In my anecdotal experience with computers plus working with some embedded telco hardware dating back to 2000 and some even earlier, some with rather old or non mainstream OS, I've never ever seen a text editor which mangled tabs. Nor I've never met anyone who seen that happen. Maybe it happened in the mainframe age, but I suspect even that software has been upgraded over time.

Sure, PEP8 an other standards prescribe spaces, and I of course always use industry standards myself too. I'm just saying that there is no technical merit for that demand. The water pipe in the monkey cage has long been shut down. The only reason to demand spaces for indent now is circular - that other standard is demanding them, therefore we need to do the same, and that other standard uses the same circular logic himself.

xigoi 522 days ago

Technical argument against tabs: they don’t play well with auto-formatters that enforce a specific line width.

Yizahi 521 days ago

Valid concern, thanks. Though I'm interested how such automatic formatting works with spaces.

maleldil 522 days ago

PEP-8 says 4 spaces. No one should be using tabs.

jokoon 522 days ago

Personally I started making a language that uses it

everyone 522 days ago

I dont think it's superficial. Having characters that are invisible affect your code is weird and bad.

Which is a shame, cus otherwise Python is good imo.. I feel like its creator just had a weird whitespace fetish or something.

sanderjd 522 days ago

It's weird and fine.

I always find this take funny, because I have lots of problems with python, but this one has always struck me as the most superficial of the common criticisms.

xigoi 522 days ago

Indentation is very much visible.

Sohcahtoa82 523 days ago

When I hear someone complain about the whitespace thing, it sends a message to me that they do not format their code well and just go willy-nilly on their indentation.

If you're properly indenting code, then it always works as intended. Proper indentation doesn't come from a desire to make the code work, it comes from a desire to make it readable. It just happens that readable means correct in Python's case.

It literally takes me zero thought to get indentation right. If you can't tell when to start or end indentation level, then I'd question if you know when you need to use an open/close brace in other languages.

I mean, yeah, sometimes copy/pasting code doesn't work precisely as intended, but all you have to do is select the code, hit Tab or Shift-Tab, and any sane editor will add/subtract an indentation level to the code.

HexDecOctBin 523 days ago

I just translated all my build scripts written in Python to straight C due to indentation issues. Not because I don't format my code properly, but because any time I refactored my code, I ended up with dozens of subtle indentation related bugs that took hours to find and fix.

If your language requires an IDE, then you have become Java.

sanderjd 522 days ago

I don't relate to this at all. I don't understand how you refactor, in either python or C or anything else, without fixing indentation after you move code around. Yes, in C you don't have to fix the indentation in order to get it to compile and run, but that doesn't mean you don't have to fix the indentation! You can't just leave it inconsistent, that's insanity.

wakamoleguy 522 days ago

Of course you can leave it inconsistent! If whitespace is insignificant, you can move things around however you want and use (frequent) runs of a code formatter to clean things up for you. If whitespace is significant, it must be fixed manually line by line.

sanderjd 521 days ago

Code formatters work just fine in python. If you're running a code formatter frequently, that is not "leaving it inconsistent".

wakamoleguy 517 days ago

If we’re talking about pasted code not having the proper indentation, that’s a major difference between languages with and without significant whitespace. A formatter can fix that in C, but not in Python. Additionally, manual fixing of the indentation is required first.

kstrauser 522 days ago

Python doesn't require an IDE, but you'll definitely want to use a programmer's editor with it. I don't know what you're using that doesn't handle its indentation correctly because I haven't seen anything like that in at least a decade, but you may wish to upgrade to at least a newer vim or emacs.

dgfitz 522 days ago

Hours? And C was a better option for scripting than python?

I’ll give you the benefit of the doubt, this sounds very curious.

HexDecOctBin 522 days ago

Pretty much. Partly because I have developed a pretty robust C standard library that I allows for writing code that is not too dissimilar from the kind of Python I was writing. And one shot processes mean that I can simply allocate memory without having to free it (and use arenas for one script that is a long-lived file-watcher).

gunian 522 days ago

why? black automatically formats code

simonw 522 days ago

What text editor do you use?

tbrownaw 522 days ago

> When I hear someone complain about the whitespace thing, it sends a message to me that they do not format their code well and just go willy-nilly on their indentation.

That's quite the assumption.

cma 523 days ago

Not being able to nest multiline lambdas into function arguments where they are called makes you have to read a lot of code backwards.

kstrauser 522 days ago

I do wish it had lambdas. That's largely mitigated by the fact you can define functions pretty much anywhere. Instead of:

  def my_func():
      another_func(lambda: ...)

you can write

  def my_func():
      def inner(): ...
      another_func(inner)

Sure, it's creating a function, naming it, then immediately throwing it away, but gets the job done with minimal extra boilerplate.

cma 522 days ago

That's what I meant by backwards though. Especially in UI OnClick code etc., I'd rather know the context that this happens on click of whichever object it is, but instead I have to write the clicked code before the code that registers it with the object, whose name has more relevant info, and then I end up having to name an extra thing too and keep the name in sync

kstrauser 522 days ago

But you can use a named function anywhere you'd use a lambda, in exactly the same way, just literally one line above where you'd pass the lambda to another function. It's not like you have to write the named function up at the top of the file. You can define it right there where it's going to be called. Truly, it's so easy and cheap to make a named function that I've never really missed having lambdas.

cma 522 days ago

Its backwards when you read it and redundant.

    def do_on_click(): # What's being clicked? 
        foo()
        bar()

    backup_system_panel.reset_button.bind(on_click=do_on_click())

Oh it's the backup system, maybe I should have named it that. Now I have to worry about reading backwards or keeping names in sync. Having to give it a descriptive name is like uneccessary comments. Giving it a temp name is ok but then you are reading bottom to top to know what is going on like you are programming in reverse polish notation or something. It can be multiple lines and scrolled off the screen before you know the context it is used in, instead of just being able to read top to bottom and get everything. Most other languages let you just stick it in line where it is used. It's error prone like C variables when they had to be declared up top.

Sometimes in other contexts it does make sense to do, but with other languages you can choose to pre-declare and name it or not. In python often you see code with all the error handling lambdas up top before you even know what is going on, when exceptions aren't a good fit.

int_19h 521 days ago

One trick for this is to use the decorator syntax, e.g.:

   @foo.on_click
   def foo_clicked(): ...

Of course, for this, foo.on_click needs to be a callable function rather than a property.

sanderjd 522 days ago

Yep, I find python's lambda syntax to be probably its worst conceived feature. But just defining a named inner function works great for all the same use cases.

xigoi 522 days ago

That has nothing to do with significant indentation. Other languages with significant indentation (Nim, CoffeeScript) support multi-line function literals.

cb321 521 days ago

Because of Python's prominence and the divisiveness of significant indents, there is a large amount of misattribution of "whatever Python's syntax choices are" to "must be needed by significant indentation". E.g., whenever I go from Nim back to Python, I get annoyed that `t = 0; for e in x: t += e` is illegal in Python (Yes, I know `sum()` exists - it's just another easy syntax example to amplify your lambdas one.)

dgfitz 522 days ago

It also makes hard-to-maintain code. Trade-offs.

tom_ 522 days ago

Python forces you to properly indent your code because the language is designed in a way that means the computer can't do it for you.

Once I'd become accustomed to languages where automatic formatting is feasible, having to do any of this sort of thing by hand started to feel like a real imposition. I didn't object to this aspect of Python when I first learned it, because it didn't feel much different from writing my C code, but now, after years of clang-format (and Visual Studio's auto format, and gofmt on the occasions I've been forced to use Google Go...) I just can't be bothered. How dare it make me press return. How dare it make me press tab. I have better things to do with my life than what I can only describe as this. fucking. shit.

xigoi 522 days ago

You have to press return instead of a semicolon, which is the same amount of keystrokes, and tab instead of a curly brace, which is fewer keystrokes. What problem do you have with that?

Also, Python has a great auto-formatter, Black.

ahartmetz 523 days ago

Yeah. It avoids the problem of indentation disagreeing with code structure and reduces visual clutter and... that's it.

tacticus 522 days ago

you can solve that with a formatter. and then you'd get consistent outputs that work reliably as you move code.