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Version: Python

Nulls

Null values indicate that a value does not exist in the data. Within Deephaven, each data type represents nulls differently and special null values are assigned. Complex data types, such as Objects, are stored as standard null or None references. Primitive types, such as doubles or integers, are stored as a single null value from the type’s range.

Example​

The following script displays Deephaven null values:

from deephaven.constants import (
    NULL_BYTE,
    NULL_SHORT,
    NULL_INT,
    NULL_LONG,
    NULL_FLOAT,
    NULL_DOUBLE,
)

nulls = {
    "byte": NULL_BYTE,
    "short": NULL_SHORT,
    "int": NULL_INT,
    "long": NULL_LONG,
    "float": NULL_FLOAT,
    "double": NULL_DOUBLE,
}
print(nulls)

Null values can be detected using the isNull filter.

from deephaven import new_table
from deephaven.column import int_col, double_col
from deephaven.constants import NULL_INT, NULL_DOUBLE

source = new_table(
    [double_col("Doubles", [NULL_DOUBLE, 0.0]), int_col("Integers", [NULL_INT, 0])]
)

result = source.update(
    formulas=["NullDoubles = isNull(Doubles)", "NullIntegers = isNull(Integers)"]
)