56 lines
1.6 KiB
Python
56 lines
1.6 KiB
Python
"""
|
|
Module loading utilities similar to Django's module_loading.
|
|
|
|
Reference implementation from Django:
|
|
https://github.com/django/django/blob/main/django/utils/module_loading.py
|
|
"""
|
|
|
|
import sys
|
|
from importlib import import_module
|
|
from typing import Any
|
|
|
|
|
|
def cached_import(module_path: str, class_name: str) -> Any:
|
|
"""
|
|
Import a module and return the named attribute/class from it, with caching.
|
|
|
|
Args:
|
|
module_path: The module path to import from
|
|
class_name: The attribute/class name to retrieve
|
|
|
|
Returns:
|
|
The imported attribute/class
|
|
"""
|
|
if not (
|
|
(module := sys.modules.get(module_path))
|
|
and (spec := getattr(module, "__spec__", None))
|
|
and getattr(spec, "_initializing", False) is False
|
|
):
|
|
module = import_module(module_path)
|
|
return getattr(module, class_name)
|
|
|
|
|
|
def import_string(dotted_path: str) -> Any:
|
|
"""
|
|
Import a dotted module path and return the attribute/class designated by
|
|
the last name in the path. Raise ImportError if the import failed.
|
|
|
|
Args:
|
|
dotted_path: Full module path to the class (e.g., 'module.submodule.ClassName')
|
|
|
|
Returns:
|
|
The imported class or attribute
|
|
|
|
Raises:
|
|
ImportError: If the module or attribute cannot be imported
|
|
"""
|
|
try:
|
|
module_path, class_name = dotted_path.rsplit(".", 1)
|
|
except ValueError as err:
|
|
raise ImportError(f"{dotted_path} doesn't look like a module path") from err
|
|
|
|
try:
|
|
return cached_import(module_path, class_name)
|
|
except AttributeError as err:
|
|
raise ImportError(f'Module "{module_path}" does not define a "{class_name}" attribute/class') from err
|