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# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
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import pytest
from nanoarrow.c_array import allocate_c_array
from nanoarrow.c_array_stream import allocate_c_array_stream
from nanoarrow.c_schema import allocate_c_schema
import nanoarrow as na
pa = pytest.importorskip("pyarrow")
class SchemaWrapper:
def __init__(self, schema):
self.schema = schema
def __arrow_c_schema__(self):
return self.schema.__arrow_c_schema__()
class ArrayWrapper:
def __init__(self, array):
self.array = array
def __arrow_c_array__(self, requested_schema=None):
return self.array.__arrow_c_array__(requested_schema=requested_schema)
class StreamWrapper:
def __init__(self, stream):
self.stream = stream
def __arrow_c_stream__(self, requested_schema=None):
return self.stream.__arrow_c_stream__(requested_schema=requested_schema)
def test_schema():
pa_schema = pa.schema([pa.field("some_name", pa.int32())])
for schema_obj in [pa_schema, SchemaWrapper(pa_schema)]:
schema = na.c_schema(schema_obj)
# some basic validation
assert schema.is_valid()
assert schema.format == "+s"
assert schema._to_string(recursive=True) == "struct<some_name: int32>"
# roundtrip
pa_schema2 = pa.schema(schema)
assert pa_schema2.equals(pa_schema)
# schemas stay valid because it exports a deep copy
del pa_schema2
assert schema.is_valid()
def test_array():
pa_arr = pa.array([1, 2, 3], pa.int32())
for arr_obj in [pa_arr, ArrayWrapper(pa_arr)]:
array = na.c_array(arr_obj)
# some basic validation
assert array.is_valid()
assert len(array) == 3
assert array.schema._to_string(recursive=True) == "int32"
# roundtrip
pa_arr2 = pa.array(array)
assert pa_arr2.equals(pa_arr)
del pa_arr2
assert array.is_valid()
def test_array_requested_schema():
pa_arr = pa.array([1, 2, 3], pa.int32())
array = na.c_array(pa_arr, schema=pa.int64())
assert array.schema.format == "l"
def test_array_stream():
pa_table = pa.table({"some_column": pa.array([1, 2, 3], pa.int32())})
for stream_obj in [pa_table, StreamWrapper(pa_table)]:
array_stream = na.c_array_stream(stream_obj)
# some basic validation
assert array_stream.is_valid()
array = array_stream.get_next()
assert len(array) == 3
assert (
array_stream.get_schema()._to_string(recursive=True)
== "struct<some_column: int32>"
)
# roundtrip
array_stream = na.c_array_stream(stream_obj)
pa_table2 = pa.table(array_stream)
assert pa_table2.equals(pa_table)
# exporting a stream marks the original object as released (it is moved)
assert not array_stream.is_valid()
# and thus exporting a second time doesn't work
with pytest.raises(RuntimeError):
pa.table(array_stream)
def test_array_stream_requested_schema():
pa_table = pa.table({"some_column": pa.array([1, 2, 3], pa.int32())})
schema2 = pa.schema([pa.field("some_column", pa.int64())])
try:
stream = na.c_array_stream(pa_table, schema=schema2)
assert stream.get_schema().child(0).format == "l"
except NotImplementedError:
# Was not implemented before pyarrow 16.0.0
pass
def test_export_invalid():
schema = allocate_c_schema()
assert schema.is_valid() is False
with pytest.raises(RuntimeError, match="schema is released"):
pa.schema(schema)
array = allocate_c_array()
assert array.is_valid() is False
with pytest.raises(RuntimeError, match="CArray is released"):
pa.array(array)
array_stream = allocate_c_array_stream()
assert array_stream.is_valid() is False
with pytest.raises(RuntimeError, match="array stream is released"):
pa.table(array_stream)
def test_import_from_c_errors():
from nanoarrow.c_array import CArray
from nanoarrow.c_array_stream import CArrayStream
from nanoarrow.c_schema import CSchema
# ensure proper error is raised in case of wrong object or wrong capsule
pa_arr = pa.array([1, 2, 3], pa.int32())
with pytest.raises(ValueError):
CSchema._import_from_c_capsule("wrong")
with pytest.raises(ValueError):
CSchema._import_from_c_capsule(pa_arr.__arrow_c_array__())
with pytest.raises(ValueError):
CArray._import_from_c_capsule("wrong", "wrong")
with pytest.raises(ValueError):
CArray._import_from_c_capsule(
pa_arr.__arrow_c_array__(), pa_arr.type.__arrow_c_schema__()
)
with pytest.raises(ValueError):
CArrayStream._import_from_c_capsule("wrong")
with pytest.raises(ValueError):
CArrayStream._import_from_c_capsule(pa_arr.__arrow_c_array__())