def from_url(cls, url: Union[str, EmailURL]) -> BaseTransport:
url = EmailURL(url)
if url.transport not in cls.mapping:
raise NotRegisteredTransportError(
f'No transport found with scheme "{url.transport}".')
klass = cls.mapping[url.transport]
if isinstance(klass, str):
klass = import_from_string(klass)
klass = cast(Type[BaseTransport], klass)
factory = getattr(klass, "from_url", None)
if factory is not None:
return factory(url)
return klass()
def test_raises_if_no_semicolon():
with pytest.raises(ImportFromStringError) as ex:
import_from_string("some.module")
assert str(ex.value) == (
'Import string must be in format: "<module>:<attribute>". '
f'Given: "some.module"')
def test_imports_attribute():
klass = import_from_string("tempfile:TemporaryFile")
assert klass is tempfile.TemporaryFile
def test_raises_if_attribute_not_found():
with pytest.raises(ImportFromStringError) as ex:
import_from_string("tempfile:MissingTemporaryFile")
assert (str(ex.value) ==
'Attribute "MissingTemporaryFile" not found in module "tempfile".')
def test_raises_if_module_not_found():
with pytest.raises(ImportFromStringError) as ex:
import_from_string("some.module:SomeClass")
assert str(ex.value) == 'Could not import module: "some.module"'