DateTimeArrowType¶

final class lsst.daf.butler.arrow_utils.DateTimeArrowType¶

Bases: ExtensionType

An Arrow extension type for astropy.time.Time, stored as TAI nanoseconds since 1970-01-01.

Attributes Summary

`bit_width`	Bit width for fixed width type.
`extension_name`	The extension type name.
`id`
`num_buffers`	Number of data buffers required to construct Array type excluding children.
`num_fields`	The number of child fields.
`storage_type`	The underlying storage type.

Methods Summary

`equals`(self, other, *[, check_metadata])	Return true if type is equivalent to passed value.
`field`(self, i)	Parameters:
`to_pandas_dtype`(self)	Return the equivalent NumPy / Pandas dtype.
`wrap_array`(self, storage)	Wrap the given storage array as an extension array.

Attributes Documentation

bit_width¶

Bit width for fixed width type.

Examples

>>> import pyarrow as pa
>>> pa.int64()
DataType(int64)
>>> pa.int64().bit_width
64

extension_name¶: The extension type name.

id¶

num_buffers¶

Number of data buffers required to construct Array type excluding children.

Examples

>>> import pyarrow as pa
>>> pa.int64().num_buffers
2
>>> pa.string().num_buffers
3

num_fields¶

The number of child fields.

Examples

>>> import pyarrow as pa
>>> pa.int64()
DataType(int64)
>>> pa.int64().num_fields
0
>>> pa.list_(pa.string())
ListType(list<item: string>)
>>> pa.list_(pa.string()).num_fields
1
>>> struct = pa.struct({'x': pa.int32(), 'y': pa.string()})
>>> struct.num_fields
2

storage_type¶: The underlying storage type.

Methods Documentation

equals(self, other, *, check_metadata=False)¶

Return true if type is equivalent to passed value.

Parameters:

otherDataType or string convertible to DataType
check_metadatabool: Whether nested Field metadata equality should be checked as well.

Returns:

is_equalbool

Examples

>>> import pyarrow as pa
>>> pa.int64().equals(pa.string())
False
>>> pa.int64().equals(pa.int64())
True

field(self, i) → Field¶

Parameters:

iint

Returns:

pyarrow.Field

to_pandas_dtype(self)¶

Return the equivalent NumPy / Pandas dtype.

Examples

>>> import pyarrow as pa
>>> pa.int64().to_pandas_dtype()
<class 'numpy.int64'>

wrap_array(self, storage)¶

Wrap the given storage array as an extension array.

Parameters:

storageArray or ChunkedArray

Returns:

arrayArray or ChunkedArray: Extension array wrapping the storage array

Navigation

DateTimeArrowType¶