importer.pyā¢1.13 kB
import importlib
from typing import Any
class ImportFromStringError(Exception):
pass
def import_from_string(import_str: Any) -> Any:
if not isinstance(import_str, str):
return import_str
module_str, _, attrs_str = import_str.partition(":")
if not module_str or not attrs_str:
message = 'Import string "{import_str}" must be in format "<module>:<attribute>".'
raise ImportFromStringError(message.format(import_str=import_str))
try:
module = importlib.import_module(module_str)
except ModuleNotFoundError as exc:
if exc.name != module_str:
raise exc from None
message = 'Could not import module "{module_str}".'
raise ImportFromStringError(message.format(module_str=module_str))
instance = module
try:
for attr_str in attrs_str.split("."):
instance = getattr(instance, attr_str)
except AttributeError:
message = 'Attribute "{attrs_str}" not found in module "{module_str}".'
raise ImportFromStringError(message.format(attrs_str=attrs_str, module_str=module_str))
return instance