def sum_(
key_mapper: Optional[Mapper[Any, float]] = None
) -> Callable[[Observable[Any]], Observable[float]]:
if key_mapper:
return compose(ops.map(key_mapper), ops.sum())
def accumulator(prev: float, cur: float) -> float:
return prev + cur
return ops.reduce(seed=0, accumulator=accumulator)
def count_(
predicate: Optional[Predicate[_T]] = None,
) -> Callable[[Observable[_T]], Observable[int]]:
if predicate:
return compose(
ops.filter(predicate),
ops.count(),
)
def reducer(n: int, _: _T) -> int:
return n + 1
counter = ops.reduce(reducer, seed=0)
return counter
def create():
return xs.pipe(ops.reduce(lambda acc, x: acc + x, 42))
def create():
return xs.pipe(ops.reduce(accumulator=lambda acc, x: acc + x))
def test_reduce_seed_none_does_not_crash(self):
reactivex.empty().pipe(ops.reduce(lambda acc, v: v,
seed=None)).subscribe()