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Title
# general
c

clean-night-52582

07/31/2020, 5:39 PM
Hey I’m trying to integrate the
isort
backend using v2 with pants version
1.30.0
. Is there a way for
isort
to know about 3rdparty dependencies? In order to sort them into a separate section from buildins and first-party files. Normally I believe it looks at the environment to tell if something came from pip. I’m not sure how to do this in pants. I’ve declared the dependencies in a file
3rdparty/requirements.txt
and invoking
python_requirements()
h

hundreds-father-404

07/31/2020, 5:48 PM
Hi Charlie! Are you using isort 4 or isort 5? Their algorithm changes for how they classify imports
c

clean-night-52582

07/31/2020, 5:52 PM
I’m using
pants.backend.python.lint.isort
I didn’t specify version.
Can use either if one is easier
h

hundreds-father-404

07/31/2020, 6:10 PM
Cool, that means that you’re using the default of isort 4, which works better. We do not pull in third party requirements when running isort. This makes it much faster because we don’t have to resolve requirements and we don’t have to invalidate the cache if you change your requirements. Instead, we recommend adding a top-level
.isort.cfg
file to your project with settings like this:
Copy code
[settings]
known_first_party=myorg,myorg2
default_section=THIRDPARTY
Replace
myorg
with the names of your top-level package, like
pants
or
django
. Then, set this in `pants.toml`:
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[isort]
config = [".isort.cfg"]
Isort 5 is still an open question how Pants should robustly support it. They changed their algorithm to be a little fancier and it will possibly require that we do include 3rd party requirements with isort, which we really want to avoid because of the implications for performance and cache invalidation.
c

clean-night-52582

07/31/2020, 6:17 PM
That makes sense of why it’s not an option. I was hoping to do the first party method since my project has a very flat structure to it and I didn’t want a huge list there. It seems like a good approach though.
h

hundreds-father-404

07/31/2020, 6:19 PM
since my project has a very flat structure to it
Got it. It may make sense to then invert it so that you set the default section to first party, and you enumerate each 3rd party req used. Although, I suspect it’s more common to add a new third party req than it is to add a new top-level package name, so it may be more robust to stick with defaulting to third party.
Btw, which Pants version are you on?
c

clean-night-52582

07/31/2020, 6:20 PM
Pants now has the idea of
module_mapping
for third party in order to do dependency inference. I wonder if there could be a solution using that to build a list of known third parties and inject that into isort
I’m
1.30.0
Using the v2 engine.
💯 1
h

hundreds-father-404

07/31/2020, 6:25 PM
Indeed, we do now have
module_mapping
! That’s an interesting idea. I think possibly we could use that to try to intelligently auto-configure the config file with the names of the modules? I think we’d be a little hesitant to modify a user’s config file like that, though. A general theme of the v2 engine and upcoming 2.0 release is making Pants less magical. We generally want you to be able to run the same tools without Pants, and it would still work.
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