Pylance "Organize Imports" overrides isort force_single_line

[wesleybl]

Environment data

• Pylance version: 2026.1.1
• OS and version: Linux (Ubuntu)
• Python version (& distribution if applicable, e.g. Anaconda): Python 3.13

Code Snippet

# pyproject.toml (isort config):
# [tool.isort]
# profile = "black"
# force_single_line = true

from setuptools import setup
from setuptools import find_packages

Repro Steps

1. Configure isort with force_single_line = true in pyproject.toml or .isort.cfg.
2. Install the ms-python.isort extension.
3. Add "source.organizeImports": "explicit" to editor.codeActionsOnSave in settings.json.
4. Open a Python file with imports from the same module on separate lines (as above).
5. Save the file.

Expected behavior

Pylance should respect the isort configuration (force_single_line = true) and keep imports from the same module on separate lines, or at minimum not run its own organize imports after isort has already sorted them:

from setuptools import find_packages
from setuptools import setup

Actual behavior

Pylance runs its own "Organize Imports" implementation after isort, overwriting isort's result and merging imports from the same module into a single line:

from setuptools import find_packages, setup

This happens because both the ms-python.isort extension and Pylance respond to the same source.organizeImports code action kind, and Pylance always runs last, discarding the isort output.

There is currently no setting in Pylance to disable only its organize imports behavior while keeping other features active. The only workarounds are:

Setting "source.organizeImports": "never", which also disables the isort extension's action on save
Using a custom formatter wrapper that chains Black + isort, bypassing source.organizeImports entirely
Pylance should either:

Detect that another provider (isort) is registered for source.organizeImports and defer to it, or
Provide a setting like "pylance.organizeImports": false to allow users to opt out of Pylance's implementation independently

Logs

N/A

[github-actions]

Hi @wesleybl, I'm an AI Support assistant here to help with your issue. While the team reviews your request, I wanted to provide some possible tips and documentation that might help you in the meantime.

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Duplicate Issues – These issues appear to be duplicates of your report.

• Sort imports is severely bugged with Pylance language server – race between the Python extension’s isort and Pylance’s own organizer causes conflicting edits. Sort imports is severely bugged with Pylance language server #23

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Similar Issues (FYI only, not solutions)

The following issues may or may not be related to your report. They are provided for reference only, as they may describe similar symptoms, affect the same feature, or address related concerns, but may not be the same issue.

• Remove unused imports on Organize Imports – expectations around sorting and removal of unused imports, and integration with isort. Remove unused imports on Organize Imports #268
• Pylance does not provide source actions for removing unused imports or sorting imports inside Jupyter Notebooks – organize imports disabled in notebook contexts. Pylance does not provide source actions for removing unused imports or sorting imports inside Jupyter Notebooks #3175

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[wesleybl]

Actually, it wasn't Pylance that was organizing the imports. I have the ruff plugin installed, and it also organizes imports. That was what was causing the problem. I added the following configuration:

"ruff.organizeImports": false,

to settings.json and it worked.