Don't raise reportFunctionMemberAccess for `__text_signature__` and `__signature__` attributes of functions

[jonathandung]

Type: Bug

The __text_signature__ and __signature__ attributes, especially when set manually, are likely meant to alter the help output of the function, pass stubtest, etc.. Though somewhat hacky, they are perfectly legitimate attributes to set on functions (I get why accessing them would create diagnostics, but maybe assignment to them should not error).

Extension version: 2026.2.101
VS Code version: Code 1.119.0 (8b640eef5a6c6089c029249d48efa5c99adf7d51, 2026-05-05T11:23:50-07:00)
OS version: Windows_NT x64 10.0.26200
Modes:

System Added Logs

2026-05-10 22:12:31.329 [info] Client: Pylance client (2026.2.101) started with python extension (2026.5.2026050801)
2026-05-10 22:12:32.230 [info] (9620): Server root directory: file:///c%3A/Users/Jonathan%20Dung/.vscode/extensions/ms-python.vscode-pylance-2026.2.101/dist
2026-05-10 22:12:32.237 [info] (9620): Pylance language server 2026.2.101 (pyright version 1.1.409, commit 34c556b7) starting
2026-05-10 22:12:32.261 [info] (9620): Starting service instance "asyncutils" for workspace "c:\Users\Jonathan Dung\asyncutils"
2026-05-10 22:12:33.670 [info] (9620): Loading background bundle file:///c%3A/Users/Jonathan%20Dung/.vscode/extensions/ms-python.vscode-pylance-2026.2.101/dist/copilot-background.bundle.js into file:///c%3A/Users/Jonathan%20Dung/asyncutils...
2026-05-10 22:12:33.800 [info] (9620): Starting Mcp server id:60395 ...
2026-05-10 22:12:33.825 [info] (9620): FG(asyncutils): Loading pyproject.toml file at c:\Users\Jonathan Dung\asyncutils\pyproject.toml
2026-05-10 22:12:33.831 [info] (9620): FG(asyncutils): Setting environmentName for service "asyncutils": "3.14.0 (global)"
2026-05-10 22:12:33.831 [info] (9620): FG(asyncutils): Setting pythonPath for service "asyncutils": "C:\Program Files\Python314\python.exe"
2026-05-10 22:12:33.832 [info] (9620): FG(asyncutils): No include entries specified; assuming c:\Users\Jonathan Dung\asyncutils
2026-05-10 22:12:33.833 [info] (9620): FG(asyncutils): Auto-excluding **/node_modules
2026-05-10 22:12:33.833 [info] (9620): FG(asyncutils): Auto-excluding **/__pycache__
2026-05-10 22:12:33.833 [info] (9620): FG(asyncutils): Auto-excluding **/.*
2026-05-10 22:12:33.948 [info] (9620): FG(asyncutils): Assuming Python version 3.14.0.final.0
2026-05-10 22:12:34.153 [info] (9620): [Editable Installs] Starting dynamic pth file resolution for Python: C:\Program Files\Python314\python.exe
2026-05-10 22:12:34.227 [info] (9620): [Editable Installs] No sandbox available for Python C:\Program Files\Python314\python.exe. Dynamic pth file resolution requires Python 3.13 or later.
2026-05-10 22:12:34.230 [info] (9620): FG(asyncutils): Found 124 source files
2026-05-10 22:12:34.823 [info] (9620): PQ(asyncutils): Priority queue background worker(2) root directory: file:///c%3A/Users/Jonathan%20Dung/.vscode/extensions/ms-python.vscode-pylance-2026.2.101/dist
2026-05-10 22:12:34.823 [info] (9620): PQ(asyncutils): Priority queue background worker(2) started
2026-05-10 22:12:34.823 [info] (9620): Settings have not changed. Skipping update.
2026-05-10 22:12:43.516 [info] (9620): FG(asyncutils): IDX(asyncutils): Indexer background runner(3) root directory: file:///c%3A/Users/Jonathan%20Dung/.vscode/extensions/ms-python.vscode-pylance-2026.2.101/dist (index)
2026-05-10 22:12:43.516 [info] (9620): FG(asyncutils): IDX(asyncutils): Indexing(3) started
2026-05-10 22:12:45.365 [info] (9620): FG(asyncutils): IDX(asyncutils): scanned(3) 574 files over 1 exec env
2026-05-10 22:12:45.768 [info] (9620): FG(asyncutils): IDX(asyncutils): indexed(3) 574 files over 1 exec env
2026-05-10 22:12:45.877 [info] (9620): FG(asyncutils): IDX(asyncutils): Indexing finished(3).

System Info

Item	Value
CPUs	11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz (8 x 2419)
GPU Status	2d_canvas: enabled GPU0: VENDOR= 0x8086, DEVICE=0x9a49 [Intel(R) Iris(R) Xe Graphics], DRIVER_VENDOR=Intel, DRIVER_VERSION=32.0.101.6737 ACTIVE GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.8328 Machine model name: Machine model version: direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off trees_in_viz: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	7.85GB (2.11GB free)
Process Argv	--crash-reporter-id 9453c078-702b-4b0c-be82-802577994672
Screen Reader	no
VM	0%

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[github-actions]

Hi @jonathandung, 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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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 or relate to the same feature, but may not be the same issue.

• unknownPylance[reportFunctionMemberAccess] error on attributes added by decorators in newest vscode/pylance releases. unknownPylance[reportFunctionMemberAccess] error on attributes added by decorators in newest vscode/pylance releases pylance-release#6403

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