How to List Pre-commit Hooks from YAML Config in Python

Parse a .pre-commit-config.yaml file with PyYAML and print every hook ID paired with its source repository.

Easy Python 3.9+ Aug 9, 2026 Modern tooling 15 views 0 copies

pre-commit yaml pyyaml config dev-tools

Requires third-party packages — install first

pip install pyyaml

Python code

28 lines

Python 3.9+

import yaml

pre_commit_config = """
repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.5.0
    hooks:
      - id: trailing-whitespace
      - id: end-of-file-fixer
      - id: check-yaml
  - repo: https://github.com/psf/black
    rev: 23.11.0
    hooks:
      - id: black
"""

def list_hooks(config_text):
    config = yaml.safe_load(config_text)
    hooks = []
    for repo in config.get("repos", []):
        repo_url = repo.get("repo", "unknown")
        for hook in repo.get("hooks", []):
            hooks.append((hook.get("id", "unknown"), repo_url))
    return hooks

if __name__ == "__main__":
    for hook_id, repo_url in list_hooks(pre_commit_config):
        print(f"{hook_id}  <-  {repo_url}")

Output

stdout

trailing-whitespace  <-  https://github.com/pre-commit/pre-commit-hooks
end-of-file-fixer  <-  https://github.com/pre-commit/pre-commit-hooks
check-yaml  <-  https://github.com/pre-commit/pre-commit-hooks
black  <-  https://github.com/psf/black

How it works

yaml.safe_load converts the YAML text into nested Python dictionaries and lists, making it trivial to walk the repo/hook structure. The get("repos", []) pattern safely handles a missing top-level key so the loop doesn't crash. Nested loops iterate each repository and then each hook inside it, collecting (hook_id, repo_url) tuples. The built-in __name__ == "__main__" guard keeps the print statement from running when the script is imported elsewhere.

Common mistakes

Using `yaml.load` instead of `yaml.safe_load`, which can execute arbitrary code
Assuming the `repos` key always exists without using `.get('repos', [])`
Forgetting that `hook.get('id')` may return None for malformed entries

Variations

Use `with open('.pre-commit-config.yaml') as f:` then `yaml.safe_load(f)` to read directly from a file instead of a string
Return a list of only hook IDs (without repo URLs) if you just need names for a quick check

Real-world use cases

Auditing which hooks a repository has enabled before merging a new contributor's PR.
Building a CI script that verifies every hook in the config is implemented and up to date.
Generating documentation that lists all linting and formatting checks for a project.

How to List Pre-commit Hooks from YAML Config in Python

Python code

Output

How it works

Common mistakes

Variations

Real-world use cases

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How it works

Common mistakes

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Real-world use cases

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