pyarrow.Scalar#

class pyarrow.Scalar#

Bases: _Weakrefable

The base class for scalars.

Notes

This class supports Python’s standard operators for element-wise operations, i.e. arithmetic (+, -, /, %, **), bitwise (&, |, ^, >>, <<) and others. They can be used directly instead of calling underlying pyarrow.compute functions explicitly.

Examples

>>> import pyarrow as pa
>>> pa.scalar(42) + pa.scalar(17)
<pyarrow.Int64Scalar: 59>

>>> pa.scalar(6) ** 3
<pyarrow.Int64Scalar: 216>

>>> arr = pa.array([1, 2, 3], type=pa.int8())
>>> val = pa.scalar(42)
>>> val - arr
<pyarrow.lib.Int64Array object at ...>
[
  41,
  40,
  39
]

__init__(*args, **kwargs)#

Methods

`__init__`(args, *kwargs)
`as_py`(self, *[, maps_as_pydicts])	Return this value as a Python representation.
`cast`(self[, target_type, safe, options, ...])	Cast scalar value to another data type.
`equals`(self, Scalar other)
`validate`(self, *[, full])	Perform validation checks.

Attributes

`is_valid`	Holds a valid (non-null) value.
`type`	Data type of the Scalar object.

as_py(self, *, maps_as_pydicts=None)#

Return this value as a Python representation.

Parameters:

maps_as_pydictsstr, optional, default None

Valid values are None, ‘lossy’, or ‘strict’. The default behavior (None), is to convert Arrow Map arrays to Python association lists (list-of-tuples) in the same order as the Arrow Map, as in [(key1, value1), (key2, value2), …].

If ‘lossy’ or ‘strict’, convert Arrow Map arrays to native Python dicts.

If ‘lossy’, whenever duplicate keys are detected, a warning will be printed. The last seen value of a duplicate key will be in the Python dictionary. If ‘strict’, this instead results in an exception being raised when detected.

cast(self, target_type=None, safe=None, options=None, memory_pool=None)#

Cast scalar value to another data type.

See pyarrow.compute.cast() for usage.

Parameters:

target_typeDataType, default None: Type to cast scalar to.
safebool, default True: Whether to check for conversion errors such as overflow.
optionsCastOptions, default None: Additional checks pass by CastOptions
memory_poolMemoryPool, optional: memory pool to use for allocations during function execution.

Returns:

scalarA Scalar of the given target data type.

equals(self, Scalar other)#

Parameters:

otherpyarrow.Scalar

Returns:

bool

is_valid#: Holds a valid (non-null) value.

type#: Data type of the Scalar object.

validate(self, *, full=False)#

Perform validation checks. An exception is raised if validation fails.

By default only cheap validation checks are run. Pass full=True for thorough validation checks (potentially O(n)).

Parameters:

fullbool, default False: If True, run expensive checks, otherwise cheap checks only.

Raises:

ArrowInvalid