Function test_custom_mean_stdev

python/pathway/tests/test_reducers.py:182–211

()

def test_custom_mean_stdev():
    left = T(
        """
            pet  |  owner  | age
            cat  | Alice   | 10
            dog  | Bob     | 9
            cat  | Alice   | 8
            dog  | Bob     | 7
        """
    )

    left_res = left.groupby(left.pet).reduce(
        left.pet, mean_stdev=custom_mean_stdev(pw.this.age)
    )

    left_res = left_res.with_columns(
        mean=pw.this.mean_stdev[0], stdev=pw.this.mean_stdev[1]
    ).without(pw.this.mean_stdev)

    assert_table_equality_wo_types(
        left_res,
        T(
            """
                pet | mean | stdev
                dog | 8    | 1
                cat | 9    | 1
            """,
            id_from=["pet"],
        ),
    )


class CustomProductWithAdditionAccumulator(pw.BaseCustomAccumulator):