ianmcook commented on code in PR #43849:
URL: https://github.com/apache/arrow/pull/43849#discussion_r1733735915
##########
docs/source/python/extending_types.rst:
##########
@@ -131,58 +131,82 @@ and serialization mechanism. The extension name and
serialized metadata
can potentially be recognized by other (non-Python) Arrow implementations
such as PySpark.
-For example, we could define a custom UUID type for 128-bit numbers which can
-be represented as ``FixedSizeBinary`` type with 16 bytes::
+For example, we could define a custom rational type for fractions which can
+be represented as a pair of integers::
- class UuidType(pa.ExtensionType):
+ import pyarrow as pa
+ import pyarrow.types as pt
+
+ class RationalType(pa.ExtensionType):
def __init__(self):
- super().__init__(pa.binary(16), "my_package.uuid")
- def __arrow_ext_serialize__(self):
- # Since we don't have a parameterized type, we don't need extra
- # metadata to be deserialized
- return b''
+ super().__init__(
+ pa.struct(
+ [
+ ("numer", pa.int32()),
+ ("denom", pa.int32()),
+ ],
+ ),
+ "my_package.rational",
+ )
+
+ def __arrow_ext_serialize__(self) -> bytes:
+ # No serialized metadata necessary
+ return b""
@classmethod
- def __arrow_ext_deserialize__(cls, storage_type, serialized):
+ def __arrow_ext_deserialize__(self, storage_type, serialized):
# Sanity checks, not required but illustrate the method signature.
- assert storage_type == pa.binary(16)
+ assert pt.is_struct(storage_type)
+ assert pt.is_int32(storage_type[0].type)
assert serialized == b''
Review Comment:
> Would it be helpful to add an issue to standardize to double quotes?
Sure, or if you just want to fix them in this PR, that's fine too. I don't
think we're too fussy about consistency of single/double quotes in examples,
but it's best to at least be consistent within one example.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
