introspection.py 文件源码

def get_model_from_path_string(root_model, path):
    """ Return a model class for a related model
    root_model is the class of the initial model
    path is like foo__bar where bar is related to foo
    """
    for path_section in path.split('__'):
        if path_section:
            try:
                field, model, direct, m2m = _get_field_by_name(root_model, path_section)
            except FieldDoesNotExist:
                return root_model
            if direct:
                if _get_remote_field(field):
                    try:
                        root_model = _get_remote_field(field).parent_model()
                    except AttributeError:
                        root_model = _get_remote_field(field).model
            else:
                if hasattr(field, 'related_model'):
                    root_model = field.related_model
                else:
                    root_model = field.model
    return root_model