def import_submodules(package: Union[str, ModuleType],
                      base_package_for_relative_import: str = None,
                      recursive: bool = True) -> Dict[str, ModuleType]:
    """
    Import all submodules of a module, recursively, including subpackages.

    Args:
        package: package (name or actual module)
        base_package_for_relative_import: path to prepend?
        recursive: import submodules too?

    Returns:
        dict: mapping from full module name to module

    """
    # http://stackoverflow.com/questions/3365740/how-to-import-all-submodules
    if isinstance(package, str):
        package = importlib.import_module(package,
                                          base_package_for_relative_import)
    results = {}
    for loader, name, is_pkg in pkgutil.walk_packages(package.__path__):
        full_name = package.__name__ + '.' + name
        log.debug("importing: {}", full_name)
        results[full_name] = importlib.import_module(full_name)
        if recursive and is_pkg:
            results.update(import_submodules(full_name))
    return results
Import all submodules of a module, recursively, including subpackages.

    Args:
        package: package (name or actual module)
        base_package_for_relative_import: path to prepend?
        recursive: import submodules too?

    Returns:
        dict: mapping from full module name to module