Parquet string serialization breaks conversion to numpy #3696
Description
Version of Awkward Array
2.8.9
Description and code to reproduce
a = ak.Array([{"foo": "bar"}, {"foo": "baz"}])
b = np.asarray(a["foo"])
ak.to_parquet(a, "test.parquet")
x = ak.from_parquet("test.parquet")
y = np.asarray(x["foo"]) # !!!Results in
File "/Users/dcm/Developer/awkward/bugex.py", line 15, in main
y = np.asarray(x["foo"])
File "/Users/dcm/Developer/awkward/src/awkward/highlevel.py", line 1548, in __array__
with ak._errors.OperationErrorContext(
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
"numpy.asarray", (self,), {"dtype": dtype, "copy": copy}
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
):
^
File "/Users/dcm/Developer/awkward/src/awkward/_errors.py", line 80, in __exit__
raise self.decorate_exception(exception_type, exception_value)
File "/Users/dcm/Developer/awkward/src/awkward/highlevel.py", line 1553, in __array__
return convert_to_array(self._layout, dtype=dtype, copy=copy)
File "/Users/dcm/Developer/awkward/src/awkward/_connect/numpy.py", line 511, in convert_to_array
out = ak.operations.to_numpy(layout, allow_missing=False)
File "/Users/dcm/Developer/awkward/src/awkward/_dispatch.py", line 67, in dispatch
next(gen_or_result)
~~~~^^^^^^^^^^^^^^^
File "/Users/dcm/Developer/awkward/src/awkward/operations/ak_to_numpy.py", line 48, in to_numpy
return _impl(array, allow_missing)
File "/Users/dcm/Developer/awkward/src/awkward/operations/ak_to_numpy.py", line 60, in _impl
return numpy_layout.to_backend_array(allow_missing=allow_missing)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/dcm/Developer/awkward/src/awkward/contents/content.py", line 1126, in to_backend_array
return self._to_backend_array(allow_missing, backend)
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/dcm/Developer/awkward/src/awkward/contents/listoffsetarray.py", line 2064, in _to_backend_array
backend[
~~~~~~~^
"awkward_NumpyArray_prepare_utf8_to_utf32_padded",
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...<2 lines>...
_max_code_points.dtype.type,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
](
^
File "/Users/dcm/Developer/awkward/src/awkward/_backends/numpy.py", line 32, in __getitem__
return NumpyKernel(awkward_cpp.cpu_kernels.kernel[index], index)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^
KeyError: ('awkward_NumpyArray_prepare_utf8_to_utf32_padded', <class 'numpy.uint8'>, <class 'numpy.int32'>, <class 'numpy.int64'>)
This error occurred while calling
numpy.asarray(
<Array ['bar', 'baz'] type='2 * string'>
dtype = None
copy = None
)
I think we just need to add kernel specializations for int32/uint32 -- should have a PR shortly.