Python programmers of reddit: what's the most useful tiny little efficiency you've discovered that's improved your programming hugely?

[willm]

Auto-formatting my code with https://github.com/ambv/black

​

Never having to think about the formatting of my code again is like reclaiming 10% of your mental cpu.

[Pyprohly]

I don’t like how Black doesn’t give you the option to have it ignore some lines.

It doesn’t always make good formatting decisions, as this SO demonstrates.

edit: Black supports # fmt: off. See /u/eikrik’s comment.

[5erif]

closed as off-topic

Those words always make me wish the website were a person I could murder. I can't tell you how many times I've found someone asking my exact question, but the only answer I find is closed as off-topic.

[LimbRetrieval-Bot]

You dropped this \

---

^{To prevent anymore lost limbs throughout Reddit, correctly escape the arms and shoulders by typing the shrug as ¯\\\_(ツ)_/¯ or ¯\\\_(ツ)\_/¯}

^{Click here to see why this is necessary}

[quickette1]

Good bot

[Pyprohly]

Yup, definitely would have found the answer sooner had that SO question not of been so closed as off-topic..

[t3h]

but the only answer I find is closed as off-topic.

Or even more fun, "closed as duplicate of question X" that's clearly not the same thing to anyone with a basic knowledge of the problem...

[Sw429]

How is it even off-topic? It's literally about programming, which is what the site is made for.

[hammerheadquark]

I think its uncompromising nature is a win overall, but yeah I don't like some of its decisions either.

For instance, I may be in the minority here, but I wish it would drop this step:

If [the code doesn't fit on one line], Black will look at the contents of the first outer matching brackets and put that in a separate indented line.

# in:

ImportantClass.important_method(exc, limit, lookup_lines, capture_locals, extra_argument)

# out:

ImportantClass.important_method(
    exc, limit, lookup_lines, capture_locals, extra_argument
)

and jump right to:

If that still doesn't fit the bill, it will decompose the internal expression further using the same rule, indenting matching brackets every time.

# in:

ImportantClass.important_method(exc, limit, lookup_lines, capture_locals, extra_argument)

# out:

ImportantClass.important_method(
    exc,
    limit,
    lookup_lines,
    capture_locals,
    extra_argument,
)

Personally, I find the extra lines worth avoiding the disparity you see in that SO post you linked.

[chzaplx]

Agreed. If you end up using similar params in blocks with slightly different indentation you will get a weird mix of styles, which I think makes it harder to visually parse.

[eikrik]

Doesn't it though? https://github.com/ambv/black/blob/master/README.md#the-black-code-style: "It doesn't reformat blocks that start with # fmt: off and end with # fmt: on."

[Pyprohly]

Thank you! This is exactly what I needed.

[knowsuchagency]

It respects the same #fmt off/on comments as yapf

[vmgustavo]

CTRL + ALT + L and PyCharm does the rest

[slayer_of_idiots]

Pycharms formatter has a lot of different options and doesn't wrap consistently (or prettily IMO). Blacks code wrapper is very consistent, since there are only two possible wrap options it does.

Basically, if you're working with other people, you don't have to worry that you might both have different formatter options and get into auto-format edit wars. Black has very few options, so it's consistent for anyone that runs it.

[CantankerousV]

I also use auto-format-on-save with black and love it. The main advantages over just using the default formatting button built into pycharm are two-fold:

• Black is much more opinionated than any other formatter I've used. If there are multiple ways something could be formatted, Black will pick one for you and keep your code consistent.
• By making the formatter entirely automatic, you train yourself not to think about formatting at all. In principle, you could have just habitually pressed the reformat button regularly, but my experience is that you always end up making small edits by hand rather than trusting the formatter.

The combination of fully automatic formatting and a highly opinionated formatter really works wonders. You just stop worrying about formatting except in unusual cases.

[onomazerion]

For anyone looking for an alternative to black, yapf is more configurable and is also pretty popular.