Pystrip

Python tool to safely remove comments, docstrings, and type annotations from source files using libcst.

Features

• Removes comments (inline and standalone)
• Removes docstrings (module, class, function)
• Removes type annotations (parameter hints, return types, variable annotations)
• Keeps regular string literals untouched
• Supports output formats: text, json, sarif, gitlab, github
• Works in CI with --check
• Supports config discovery and parallel processing

What pystrip will not remove

• String literals that are not docstrings. A string only counts as a docstring when it is the first statement in a module, class, or function body.
• String literals that merely look like comments, such as "value # not a comment".
• Arbitrary strings later in a body, even if they are standalone expression statements.
• Shebang lines like #!/usr/bin/env python3 unless --remove-shebang is set.
• Files that fail to parse as Python. By default the run stops on the first such error; with --continue-on-error, pystrip reports the failure and keeps processing other files.

Docstring detection is syntax-based, not text-based. That means pystrip does not try to guess intent from quote style or wording; it only removes a literal string expression in the docstring position.

Installation

pip install pystrip

Usage

# Check mode (CI)
pystrip . --check

# Apply changes in place
pystrip ./src/ --in-place

# Read from stdin and write stripped code to stdout
pystrip - < input.py > output.py

usage: pystrip [-h] [--exclude PATH] [--exclude-glob PATTERN] [--keep-docstrings] [--keep-comments] [--keep-type-annotations] [--keep-blank] [--remove-shebang] [--use-pass] [--check]
               [--diff] [--in-place] [--output-dir DIR] [--no-recursive] [--jobs N] [--config PATH] [--format {text,json,sarif,gitlab,github}] [--quiet] [--verbose]
               [--continue-on-error]
               [paths ...]

Remove comments and docstrings from Python source files.

positional arguments:
  paths                 Files or directories to process (default: ['.'])

options:
  -h, --help            show this help message and exit
  --exclude PATH        Exclude a file or directory path (repeatable) (default: None)
  --exclude-glob PATTERN
                        Exclude paths by glob pattern (repeatable) (default: None)
  --keep-docstrings     Keep docstrings and only strip comments (default: None)
  --keep-comments       Keep comments and only strip docstrings (default: None)
  --keep-type-annotations
                        Keep type annotations and only strip comments/docstrings (default: None)
  --keep-blank          Keep blank lines introduced by comment removal (default: None)
  --remove-shebang      Remove shebang lines (#!/...) from files (kept by default) (default: None)
  --use-pass            Use 'pass' instead of '...' for empty body placeholders (default: None)
  --check               Do not write files; exit with code 1 if any file would change (default: False)
  --diff                Print unified diffs for changed files (default: False)
  --in-place            Write stripped output back to each input file (default: False)
  --output-dir DIR      Write changed files into DIR instead of modifying inputs (default: None)
  --no-recursive        Process only direct child files of each directory path (default: True)
  --jobs N              Number of worker processes to use (default: None)
  --config PATH         Load configuration from a specific TOML file (default: None)
  --format {text,json,sarif,gitlab,github}
                        Output format for violations (default: None)
  --quiet               Suppress progress and summary output (default: False)
  --verbose             Print detailed removal diagnostics (default: False)
  --continue-on-error   Continue processing remaining files when a file fails to parse/process (default: False)

Output example:

⠇ Processing 10 file(s)...
src/pystrip/__init__.py:1:0: DOCSTRING_REMOVED Module docstring removed
src/pystrip/__main__.py:1:0: DOCSTRING_REMOVED Module docstring removed
...
src/pystrip/visitor.py:1:0: DOCSTRING_REMOVED Module docstring removed
Changed 10 file(s), 63 violation(s), 26 docstring(s), 37 comment(s), 0 annotation(s).

When using - as the sole input path, pystrip reads source from stdin. In normal mode it writes stripped code to stdout; in --check mode it emits violations instead. --in-place, --output-dir, and --diff are not available with stdin input.

Configuration

Use either pyproject.toml ([tool.pystrip]) or .pystrip.toml ([pystrip]). pyproject.toml is recommended when pystrip is part of a project; .pystrip.toml is useful for standalone usage. Invalid config values (for example jobs = "4") fail fast with exit code 2 and a clear error message.

[tool.pystrip]
remove_comments = true
remove_docstrings = true
remove_blank_lines = true
remove_type_annotations = true
exclude = ["tests/"]
exclude_glob = ["*.generated.py"]
jobs = 4

Output and CI

# GitHub annotations
pystrip . --check --format github

# GitLab code-quality report
pystrip . --check --format gitlab > gl-code-quality-report.json

Development

Developer setup, quality checks, and contribution workflow are documented in docs/development.md.

Exit Codes