Transform

This module provides a low-level hook mechanism to transform the source code of a package or module during its import. It must be imported before any other packages and modules that you want to hook.

Effectful

This package has an effectful behavior: modifying the sys.meta_path finder list, which will affect the import process, and is sensitive to the order of imports.

Normally you would use adapters defined in the impt package, instead of directly using the low level register_transform_hook function.

TransformPathFinder

A subclass of importlib.machinery.PathFinder that injects TransformSourceFileLoader to the import process.

TransformSourceFileLoader

A subclass of importlib.machinery.SourceFileLoader that applies all registered hooks to the source code of a module or package during import.

Implementation

This loader will directly read the source code from the .py file, completely ignoring the .pyc file. The transformed source code will not have a bytecode cache (.pyc) generated. If your file system has high latency, this may slow down the import process.

register_transform_hook(name, hook)

Register a hook function to replace the source code of a module or package.

Parameters:

Name	Type	Description	Default
name	str	The name of the module or package to hook.	required
hook	Callable[[str], str]	The hook function that takes the original source code as input and returns the transformed source code.	required