stolid
A flake8 plugin that enforces opinionated Python coding conventions for clean, maintainable code.
Stolid encourages:
Composition over inheritance
Dependency injection over mocking
Protocol-based typing over abstract base classes
Immutable dataclasses
Small, focused functions and classes
Installation
pip install stolid
Usage
Run stolid as a module to check your code:
python -m stolid your_package/
python -m stolid is the unified entry point. It runs the flake8 plugin (which emits every per-file SLDxxx code) and then the cross-file scanners that produce the SLD80x public-contract diagnostics, exiting with the worst of the two stages’ exit codes. Paths default to . if none are given.
Running flake8 directly still works and is fine for editor integration, but it only loads the in-file plugin — the SLD80x cross-file checks require the workspace-wide view that python -m stolid provides:
flake8 your_code.py # in-file SLDxxx only, no SLD80x
Error Codes
Every diagnostic is an SLDxxx code, grouped by leading digit so a whole family can be reasoned about — or silenced — together:
SLD1xx — testing and dynamic execution: no unittest.mock.patch, no exec / eval / __import__.
SLD2xx — abstract base classes and imports: prefer Protocol over ABC, keep every import at the top of the module (Temporal’s with workflow.unsafe.imports_passed_through(): block counts as part of that header), and keep any single module’s imported surface narrow.
SLD3xx — object-oriented design: boring constructors, no private methods, and real enums instead of stringly-typed values.
SLD4xx — inheritance: no subclassing of concrete classes.
SLD5xx — dataclass configuration: frozen, slots, and kw_only on every dataclass.
SLD6xx — code complexity: bounded function weight, argument and method counts, context-manager-friendly cleanup, and enumerate / iteration over manual range(len(...)) and while-index walks.
SLD7xx — naming: no vague words, no shadowing of stdlib names, no confusable near-duplicate names.
SLD8xx — cross-file contracts, documentation, and import-graph architecture: the checks that need a workspace-wide view and run via python -m stolid.
SLD9xx — privacy: the underscore-prefix convention across attributes, modules, and imports.
The full catalog — every code with its rationale and bad/good examples — lives in the documentation under doc/error-codes/ (one page per family).
Configuration
Stolid follows standard flake8 configuration. Add to your setup.cfg or .flake8:
[flake8]
extend-ignore = SLD301,SLD302
Or use per-file ignores:
[flake8]
per-file-ignores =
tests/*:SLD301,SLD302
Development
pip install nox
# Run all checks
nox
# Run specific sessions
nox -s tests # Run tests with coverage
nox -s lint # Run black and flake8
nox -s mypy # Run type checking
License
MIT License. See LICENSE for details.
Metadata
Release files for stolid 2026.10.26.59175
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | Provenance | Actions |
|---|---|---|---|---|
| stolid-2026.10.26.59175.tar.gz | 97.5 kB | With provenance | Details for stolid-2026.10.26.59175.tar.gz |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Actions Reset |
|---|---|---|---|---|
| stolid-2026.10.26.59175-py3-none-any.whl | Python 3 | none | any | Details for stolid-2026.10.26.59175-py3-none-any.whl |
Total release size: 228.8 kB
Release files / stolid-2026.10.26.59175.tar.gz
| Download URL | stolid-2026.10.26.59175.tar.gz |
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| Size | 97.5 kB |
| Tags | Source |
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| Uploaded via |
twine/6.1.0 CPython/3.13.13
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