lenskit.data.accum

Data accumulation support

Classes

Accumulator	Protocol implemented by data accumulators.
AccumulatorFactory	Base class for protocol classes.
ValueStatAccumulator	An accumulator for single real values, computing basic statistics.
ValueStatistics	Collected statitsics from ValueAccumulator.

Package Contents

class lenskit.data.accum.Accumulator[X, R]

Bases: Protocol

Protocol implemented by data accumulators.

add(value)

Add a single value to this accumulator.

Parameters:

value (X)

Return type:

None

accumulate()

Compute the accumulated value from this accumulator.

Return type:

R

class lenskit.data.accum.AccumulatorFactory[X, R]

Bases: Protocol

Base class for protocol classes.

Protocol classes are defined as:

class Proto(Protocol):
    def meth(self) -> int:
        ...

Such classes are primarily used with static type checkers that recognize structural subtyping (static duck-typing).

For example:

class C:
    def meth(self) -> int:
        return 0

def func(x: Proto) -> int:
    return x.meth()

func(C())  # Passes static type check

See PEP 544 for details. Protocol classes decorated with @typing.runtime_checkable act as simple-minded runtime protocols that check only the presence of given attributes, ignoring their type signatures. Protocol classes can be generic, they are defined as:

class GenProto[T](Protocol):
    def meth(self) -> T:
        ...

create_accumulator()

Create an accumulator for the results of this object.

Returns:

An accumulator.

Return type:

Accumulator[X, R]

class lenskit.data.accum.ValueStatAccumulator

Bases: lenskit.data.accum._proto.Accumulator[float | None, ValueStatistics]

An accumulator for single real values, computing basic statistics.

property values: numpy.ndarray[tuple[int], numpy.dtype[numpy.float64]]

Return type:

numpy.ndarray[tuple[int], numpy.dtype[numpy.float64]]

__len__()

Return type:

int

add(value)

Add a single value to this accumulator.

Parameters:

value (float | None)

accumulate()

Compute the accumulated value from this accumulator.

Return type:

ValueStatistics

class lenskit.data.accum.ValueStatistics

Bases: TypedDict

Collected statitsics from ValueAccumulator.

n: int

mean: float

median: float

std: float