pyarrow.register_extension_type

pyarrow.register_extension_type(ext_type)

注册一个 Python 扩展类型。

注册基于扩展名称（因此不同的注册类型需要唯一的扩展名称）。注册时需要一个扩展类型的实例，但注册完成后，该子类的所有实例（无论类型如何参数化）均可使用。

参数:

ext_typeBaseExtensionType instance

要注册的 ExtensionType 子类。

示例

定义一个继承自 ExtensionType 的 RationalType 扩展类型

>>> import pyarrow as pa
>>> class RationalType(pa.ExtensionType):
...     def __init__(self, data_type: pa.DataType):
...         if not pa.types.is_integer(data_type):
...             raise TypeError(f"data_type must be an integer type not {data_type}")
...         super().__init__(
...             pa.struct(
...                 [
...                     ("numer", data_type),
...                     ("denom", data_type),
...                 ],
...             ),
...             # N.B. This name does _not_ reference `data_type` so deserialization
...             # will work for _any_ integer `data_type` after registration
...             "my_package.rational",
...         )
...     def __arrow_ext_serialize__(self) -> bytes:
...         # No parameters are necessary
...         return b""
...     @classmethod
...     def __arrow_ext_deserialize__(cls, storage_type, serialized):
...         # return an instance of this subclass
...         return RationalType(storage_type[0].type)

注册该扩展类型

>>> pa.register_extension_type(RationalType(pa.int64()))

取消注册该扩展类型

>>> pa.unregister_extension_type("my_package.rational")