def map(
self,
transformation: typing.Union[typing.Callable[[ValueT], AnotherValueT],
str],
) -> LazyIterator[AnotherValueT]:
"""Map the values to a different value.
Parameters
----------
transformation : typing.Union[typing.Callable[[ValueT], builtins.bool], builtins.str]
The function to use to map the attribute. This may alternatively
be a string attribute name to replace the input value with. You
can provide nested attributes using the `.` operator.
Returns
-------
LazyIterator[AnotherValueT]
`LazyIterator` that maps each value to another value.
"""
if isinstance(transformation, str):
transformation = typing.cast(
"spel.AttrGetter[ValueT, AnotherValueT]",
spel.AttrGetter(transformation))
return _MappingLazyIterator(self, transformation)
def __init__(
self,
attr_name: str,
expected_value: typing.Any,
cast: typing.Optional[typing.Callable[[ValueT], typing.Any]] = None,
) -> None:
self.expected_value = expected_value
self.attr_getter: spel.AttrGetter[
ValueT, typing.Any] = spel.AttrGetter(attr_name)
self.cast = cast