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.CommandLineWrapperHook

class brainprep.decorators.CommandLineWrapperHook[source]

Bases: Hook

Perform command line wrapper-specific preprocessing and output validation.

This Hook provides two core features:

  1. Execute command-line operations in normal (non-dry run) mode.

  2. Recursively validates all generated output files.

Examples

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

>>> @step(
...     hooks=[CommandLineWrapperHook()]
... )
... def ls_command(my_dir):
...     return ["ls", my_dir]

>>> with Config(dryrun=True):
...     ls_command("/tmp")
[command] - ls /tmp
after_call(outputs)[source]

Transform and inspect outputs after the function call.

This method executes command-line operations in normal (non-dry run) mode, 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.

Raises:
ValueError

If the decorated function does not return a valid command specification.