Patchy

Patchy is a Python library that allows patching the inner source code of Python functions at runtime. Unlike traditional monkey patching, which replaces function objects, Patchy modifies the function's `__code__` attribute, ensuring that all references to the function (even those imported elsewhere) reflect the new behavior. It achieves this by using the standard `patch` command-line utility to apply diffs to the function's source code. The current version is 2.10.0, and it generally follows a release cadence tied to bug fixes and feature enhancements, compatible with Python 3.9 to 3.14.