Interopability with black

[ambv]

Hey, Timothy! Thanks for isort, it's a very useful project.

I made an opinionated formatter, Black. Quite a few of my users are also isort users. That's great, I don't want to have to perform import sorting in Black. However, there's a small issue.

None of isort's multiline modes fits what Black is doing. Black wraps lines like this:

• try to fit everything in one line; if you can't then
• indent the contents of the parens one level and try to fit those in one line; if you can't then
• explode one element per line.

The second step in Black's algorithm is like your mode 5, and the third is like mode 3. I'd like to create a pull request for isort to introduce mode 8 (5+3) that does what Black does in this scenario. This would enable Black and isort to co-exist and keep consistent import styling.

Would you accept such pull request?

(I initially wrote this on Twitter but this belongs here better.)

[audiolion]

@timothycrosley if you would accept a PR for this it would be fantastic!

[ambv]

In fact, Black now does what "Mode 3 + trailing commas" is doing in isort. This is no longer necessary.

[jbmusso]

Unsure whether this is a black or isort thing, but I believe there's a bit of overlap about how many lines are added after imports when using both libraries.

When using VSCode with both libraries set to format on save, the following script will be formatted alternatively with one or two line after imports. The two outputs will be set alternatively:

from collections import Mapping
from typing import Optional

class Headers:
    def __init__(seq: Optional[Mapping] = None, encoding: str = "utf-8") -> None: ...

Will output alternatively (1 line after imports):

from collections import Mapping
from typing import Optional

class Headers:
    def __init__(seq: Optional[Mapping] = None, encoding: str = "utf-8") -> None: ...

and (2 lines after imports):

from collections import Mapping
from typing import Optional


class Headers:
    def __init__(seq: Optional[Mapping] = None, encoding: str = "utf-8") -> None: ...

... back and forth.

I don't want to hijack this issue, so maybe this should be better off discussed as a distinct issue. I'm unsure whether it should be created on black or isort repositories though :). Since the initial discuss interop between the two libraries, I think it's best to start here and move somewhere else.

Thanks for creating these nice libraries.

[ambv]

Thanks for reopening. Black has since adopted what is almost exactly mode 3 in isort. There are a few edge cases that we can work through to ensure the tools are perfectly matched but they should be pretty close already :-)

[timothycrosley]

@ambv sounds good!

Mostly, I realized this came up during a period where I was not as attentive to this project as I aim to be - and have been in the past. For the next release of isort in a week or so, I would like to ensure that there is an included black profile so that users don't have to mess with a ton of settings to use the two tools together. I'll start with the settings listed on the black GitHub page. And please, feel empowered to let me know of any incompatibilities and I'll do my best to resolve them in short order.

Thanks!

~Timothy

P.S. black is very cool, and something I've wanted to exist in the Python world for some time. I've introduced it in my work environment with great success and plan on using it with my open source code bases as well. So interoperability is very practically important for me :).

[shreyasbapat]

black is very cool, and something I've wanted to exist in the Python world for some time. I've introduced it in my work environment with great success and plan on using it with my open source code bases as well. So interoperability is very practically important for me

That is so nice to hear! Infact we use both of the awesome tools. i.e. black and isort in our project https://github.com/einsteinpy/einsteinpy . And this incompatibility creates a lot of issues. Can we not add a CI check for every PR to check if compatibility with black is retained?