yprint

yprint prefixes stdout/stderr lines with a colored call stack breadcrumb. It does this by preloading a small C shim that intercepts writes and lets the Python runtime update a per-thread prefix.

Install

pip install yprint

Usage

yprint -- python your_script.py
yprint -- bash -c 'python your_script.py'

Options

• --only PATH (repeatable): Only show frames under the given path(s).
• --prefix-width N: Fixed width for the prefix column.

Environment

• YPRINT_ONLY: Colon-separated list of allowed paths (same as --only).
• YPRINT_PREFIX_WIDTH: Fixed width for the prefix column.
• YPRINT_COLOR: always or never to force color on/off.
• YPRINT_CACHE_DIR: Override where the preload library is compiled.
• YPRINT_ENABLE: Set to 1 to auto-enable via sitecustomize.

yprint compiles the preload library on first run; a C compiler (cc) must be available.

Dev / Release

pip install -e ".[dev]"
python -m build
python -m twine upload dist/*