Note

This page is a reference documentation. It only explains the class signature, and not how to use it. Please refer to the user guide for the big picture.

brainprep.decorators.PythonWrapperHook

class brainprep.decorators.PythonWrapperHook

Bases: Hook

Perform Python wrapper-specific preprocessing and output validation.

This hook provides two core features:

1. Automatically injects a dryrun argument.

2. Recursively validates all generated output files.

Raises:

ValueError

If invalid wrapper type is specified.

Examples

>>> from brainprep.decorators import step, PythonWrapperHook
>>> from brainprep.config import Config

>>> @step(
...     hooks=[PythonWrapperHook()]
... )
... def ls_command(my_dir, dryrun=False):
...     if dryrun:
...         return None
...     return os.listdir(my_dir)

>>> with Config(dryrun=True):
...     ls_command("/tmp")

after_call(outputs)

Transform and inspect outputs after the function call.

This method inspects the output returned by the decorated function, recursively validates each file path, and normalizes the return type:

• None is returned unchanged.

• A single-file output is returned as a File.

• Multiple files are returned as a tuple[File].

Parameters:

outputsFile | tuple[File] | None

The output file or tuple of files returned by the decorated function, or None if no output was produced.

Returns:

outputsFile | tuple[File] | None

The validated output.

before_call(func, inputs)

Transform and inspect inputs before the function call.

Parameters:

funcCallable

The function to be decorated.

inputsdict[str, Any]

Positional and keyword arguments passed to func.

Returns:

inputsdict[str, Any]

Positional and keyword arguments passed to func with the dryrun parameter set.

Raises:

ValueError

If the decorated function have no dryrun keyword argument.