1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
import importlib
import typing
class ImportFromStringError(Exception):
pass
def import_from_string(import_str: str) -> typing.Any:
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 ImportError 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 as exc:
message = 'Attribute "{attrs_str}" not found in module "{module_str}".'
raise ImportFromStringError(
message.format(attrs_str=attrs_str, module_str=module_str)
)
return instance
|
