sybil-extras
Additions to Sybil, the documentation testing tool.
Decision gist · record as of 2026-08-14
Yes. sybil-extras fills a real gap for projects that test documentation code examples and need more control than Sybil's built-in evaluators provide. It is actively maintained, has no known vulnerabilities, installs cleanly, and supports current Python versions (3.11–3.14). Install it if you use Sybil and need shell command execution, multi-evaluator chains, or thread-safe concurrent testing.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.11 or later; Sybil must be installed as a runtime dependency.
- Low friction install with a pure-Python wheel.
- Actively maintained with a recent release (26 days old) and no known vulnerabilities.
License · maintenance · safety
MIT (permissive) — MIT license permits free use, modification, and distribution with minimal restrictions, making it suitable for both open-source and commercial projects.
last release 2026-07-19 (26 days) · last repo commit 2026-08-14 · 3 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 186,506 downloads/mo, #9,983 on PyPI
Alternatives
Verify before relying
pip install sybil-extras
from sybil import Sybil
from sybil.parsers.rest.codeblock import CodeBlockParser
from sybil_extras.evaluators.multi import MultiEvaluator
from sybil_extras.evaluators.python import PythonEvaluator
evaluators = [PythonEvaluator()]
multi = MultiEvaluator(evaluators=evaluators)
parser = CodeBlockParser(language="python", evaluator=multi)
sybil = Sybil(parsers=[parser])
pytest_collect_file = sybil.pytest()- Whether ThreadSafeSkipParser fully resolves race conditions in all concurrent evaluation scenarios beyond the documented simplistix/sybil#166 issue
- Performance characteristics when accumulating large numbers of code blocks or running shell evaluators across many examples
What it is and what it does
sybil-extras is a companion package to Sybil that adds optional evaluators and parsers for testing code examples embedded in documentation. It lets you run multiple evaluators on the same code block, execute shell commands (like mypy) against examples, accumulate code blocks for grouped testing, and define custom skip directives with thread-safe semantics. The package is designed for projects that use reStructuredText, Markdown, MyST, MDX, or Djot formats and want to validate that documentation code examples actually work.
You install it alongside Sybil and use its evaluators and parsers in your Sybil configuration. Common workflows include wrapping a custom validation function in MultiEvaluator to apply multiple checks, using ShellCommandEvaluator to run linters or type checkers on code blocks, or using ThreadSafeSkipParser when pytest runs examples concurrently across threads. The package handles file I/O, temporary file creation, and namespace management so you focus on what to test.
Use it for
- Run mypy or other type checkers on Python code blocks in documentation to catch type errors before release
- Apply multiple validation rules to the same code example using MultiEvaluator (e.g., length checks plus execution)
- Test code examples concurrently across threads without race conditions in skip-directive evaluation
- Accumulate related code blocks from a single document to test them as a group or sequence
- Format or auto-fix code blocks and write the changes back to the source documentation
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
sybil-extras fills a real gap for projects that test documentation code examples and need more control than Sybil's built-in evaluators provide. It is actively maintained, has no known vulnerabilities, installs cleanly, and supports current Python versions (3.11–3.14). Install it if you use Sybil and need shell command execution, multi-evaluator chains, or thread-safe concurrent testing.
Install
sybil-extras on PyPI
Before you install
Low friction install with a pure-Python wheel. Actively maintained with a recent release (26 days old) and no known vulnerabilities. Requires Python 3.11 or later and depends on four runtime packages including sybil, beartype, and markdown-it-py.
Requires Python 3.11 or later; Sybil must be installed as a runtime dependency.
License in practice
MIT license permits free use, modification, and distribution with minimal restrictions, making it suitable for both open-source and commercial projects.
Quickstart
pip install sybil-extras
from sybil import Sybil
from sybil.parsers.rest.codeblock import CodeBlockParser
from sybil_extras.evaluators.multi import MultiEvaluator
from sybil_extras.evaluators.python import PythonEvaluator
evaluators = [PythonEvaluator()]
multi = MultiEvaluator(evaluators=evaluators)
parser = CodeBlockParser(language="python", evaluator=multi)
sybil = Sybil(parsers=[parser])
pytest_collect_file = sybil.pytest()Verify before relying
- Whether ThreadSafeSkipParser fully resolves race conditions in all concurrent evaluation scenarios beyond the documented simplistix/sybil#166 issue
- Performance characteristics when accumulating large numbers of code blocks or running shell evaluators across many examples
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.11 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 4 packagesbeartypemarkdown-it-pymyst-parsersybil |
| Maintenance | Actively maintained 26 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 186,506 / month, #9,983 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableEnvironment :: Web EnvironmentOperating System :: Microsoft :: WindowsOperating System :: POSIXProgramming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14 |
Evidence: sybil_extras-2026.7.19-py3-none-any.whl
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See also sybil · sphinx-substitution-extensions · openevals · sphinx_mdinclude · sphinx-prompt · pytest-markdown-docs · myst-parser · sphinxcontrib-runcmd · doccmd · jupyter-sphinx