Dynamic Importing

Functions for dynamically importing from Python modules.

concoursetools.importing.import_single_class_from_module(file_path, parent_class, class_name=None)

Import the resource class from the module.

Similar to import_classes_from_module(), but ensures only one class is returned.

Parameters:

• file_path (Path) – The location of the module as a file path.

• class_name (str | None) – The name of the class to extract. Required if multiple are returned.

• parent_class (type[object]) – All subclasses of this class defined within the module (not imported from elsewhere) will be extracted.

Return type:

type[object]

Returns:

The extracted class.

Raises:

RuntimeError – If too many or too few classes are available in the module, unless the class name is specified.

concoursetools.importing.import_classes_from_module(file_path, parent_class)

Import all available resource classes from the module.

Parameters:

• file_path (Path) – The location of the module as a file path.

• parent_class (type[object]) – All subclasses of this class defined within the module (not imported from elsewhere) will be extracted.

Return type:

dict[str, type[object]]

Returns:

A mapping of class name to class.

concoursetools.importing.file_path_to_import_path(file_path)

Convert a file path to an import path.

Parameters:

file_path (Path) – The path to a Python file.

Raises:

ValueError – If the path doesn’t end in a ‘.py’ extension.

Example:

>>> file_path_to_import_path(Path("module.py"))
'module'
>>> file_path_to_import_path(Path("path/to/module.py"))
'path.to.module'

Return type:

str

concoursetools.importing.import_py_file(import_path, file_path)

Import a .py file as a module.

This is done using a standard Python recipe via importlib.util.

Parameters:

• import_path (str) – The import path added to sys.modules.

• file_path (Path) – The path to the .py module.

Return type:

ModuleType

Returns:

The imported module.

Raises:

FileNotFoundError – If the path does not exist.

concoursetools.importing.edit_sys_path(prepend=(), append=())

Temporarily add to sys.path within a context manager.

Parameters:

• prepend (Sequence[Path]) – A sequence of paths to add to sys.path before the current entries.

• append (Sequence[Path]) – A sequence of paths to add to sys.path after the current entries.

Seealso:

This is used to enable local imports for the import_py_file().

Return type:

Generator[None]