ungrouped-imports / wrong-import-order : FP because only two isort's options are taken into account

[webknjaz]

Current problem

There's this PEP 421 implicit namespace we're using. I'll call it an ecosystem_namespace in this example. It has a special project providing a ecosystem_namespace.interfaces which is kinda a platform spec or a framework for all the other projects in this namespace. So it must always be imported before any other packages in the namespace, including the local ones.

When I configure isort as follows

# .isort.cfg
[settings]
combine_as_imports = true
default_section = THIRDPARTY
honor_noqa = true
include_trailing_comma = true
indent = 4
known_first_party = ecosystem_namespace.projectlocal_subnamespace, ecosystem_namespace.another_projectlocal_subnamespace
known_frameworks = cherrypy, django
known_platforms = ecosystem_namespace.interfaces
known_testing = hypothesis, pytest
line_length = 79
lines_after_imports = 2
multi_line_output = 3
no_lines_before = LOCALFOLDER
sections = FUTURE, STDLIB, TESTING, FRAMEWORKS, PLATFORMS, THIRDPARTY, FIRSTPARTY, LOCALFOLDER
src_paths = src/*/*
use_parentheses = true
verbose = true

it helps me get the following order in the import section structure:

# src/ecosystem_namespace/projectlocal_subnamespace/api.py

from __futures__ import annotations

import os

import hypothesis
import pytest

import cheroot

import ecosystem_namespace.interfaces

import octomachinery

from ecosystem_namespace.projectlocal_subnamespace import smth

isort is able to understand that ecosystem_namespace.interfaces is a separate thing that must reside in its own category in a defined place.

However, pylint yields ungrouped-imports and wrong-import-order, despite relying on isort internally.

Additionally, the error messages in the pylint output imply that it treats the namespace (ecosystem_namespace) as a first-party package, which is nowhere near being true.

src/ecosystem_namespace/projectlocal_subnamespace/plugins.py:13:0: C0411: third party import "octomachinery" should be placed before first party import "ecosystem_namespace.interfaces._temporary_private_api.detect_runtime"  (wrong-import-order)
src/ecosystem_namespace/projectlocal_subnamespace/plugins.py:15:0: C0412: Imports from package ecosystem_namespace are not grouped (ungrouped-imports)

Desired solution

I believe, the ungrouped-imports and wrong-import-order checks should always pass when the import order matches the existing isort configuration. And it should be able to understand that namespace packages aren't first-party.

Additional context

Looking into

pylint/pylint/utils/utils.py

Lines 365 to 366 in 0972ba5

	extra_standard_library=config.known_standard_library,
	known_third_party=config.known_third_party,

, it looks like pylint only special-cases first-party and third-party categories but is ignorant about any other sections defined additionally. Perhaps, this needs to change.