pyarray now serializable

Author: Christopher Doris

docs/src/releasenotes.md

@@ -3,6 +3,7 @@
 ## Unreleased
 * New unexported functions: `python_executable_path`, `python_library_path`, `python_library_handle` and `python_version`.
 * `Py` is now treated as a scalar when broadcasting.
+* `PyArray` is now serializable.
 * Bug fixes.
 
 ## 0.9.15 (2023-10-25)

src/Compat/Compat.jl

@@ -8,7 +8,7 @@ module Compat
     using ..Core
     using ..Core: C, Utils, pynew, incref, getptr, pycopy!, pymodulehooks, pyisnull, pybytes_asvector, pysysmodule, pyosmodule, pystr_fromUTF8
     using ..Convert: pyconvert, @pyconvert
-    using ..Wrap: PyPandasDataFrame
+    using ..Wrap: PyArray, PyPandasDataFrame
     using Serialization: Serialization, AbstractSerializer, serialize, deserialize
     using Tables: Tables
     using Requires: @require

src/Compat/serialization.jl

@@ -42,3 +42,19 @@ function Serialization.serialize(s::AbstractSerializer, x::PyException)
 end
 
 Serialization.deserialize(s::AbstractSerializer, ::Type{PyException}) = PyException(deserialize_py(s))
+
+### PyArray
+#
+# This type holds a pointer and a handle (usually a python memoryview or capsule) which are
+# not serializable by default, and even if they were would not be consistent after
+# serializing each field independently. So we just serialize the wrapped Python object.
+
+function Serialization.serialize(s::AbstractSerializer, x::PyArray)
+    Serialization.serialize_type(s, typeof(x), false)
+    serialize_py(s, x.py)
+end
+
+function Serialization.deserialize(s::AbstractSerializer, ::Type{T}) where {T<:PyArray}
+    # TODO: set buffer and array args too?
+    T(deserialize_py(s); copy=false)
+end

test/Wrap.jl

@@ -69,6 +69,19 @@
         @test y == [1, 2, 3]
         @test z == [1, 2, 3]
     end
+    @testset "serialize" begin
+        using Serialization: serialize, deserialize
+        io = IOBuffer()
+        serialize(io, y)
+        seekstart(io)
+        y2 = deserialize(io)
+        @test typeof(y) == typeof(y2)
+        @test eltype(y) == eltype(y2)
+        @test ndims(y) == ndims(y2)
+        @test size(y) == size(y2)
+        @test strides(y) == strides(y2)
+        @test y == y2
+    end
 end
 
 @testitem "PyDict" begin