def map(self, func):
"""
Applies a Map transformation on a :class:`DataStream`.
The transformation calls a :class:`ray.streaming.function.MapFunction`
for each element of the DataStream.
Args:
func: The MapFunction that is called for each element of the
DataStream. If `func` is a python function instead of a subclass
of MapFunction, it will be wrapped as SimpleMapFunction.
Returns:
A new data stream transformed by the MapFunction.
"""
if not isinstance(func, function.MapFunction):
func = function.SimpleMapFunction(func)
j_func = self._gateway_client().create_py_func(
function.serialize(func))
j_stream = self._gateway_client(). \
call_method(self._j_stream, "map", j_func)
return DataStream(self, j_stream)
def test_create_operator():
map_func = function.SimpleMapFunction(lambda x: x)
map_operator = operator.create_operator(map_func)
assert type(map_operator) is operator.MapOperator