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Posted to issues@iceberg.apache.org by GitBox <gi...@apache.org> on 2021/07/28 20:08:15 UTC
[GitHub] [iceberg] jun-he commented on a change in pull request #2884: [python] Adding utility functions for converting iceberg to arrow
jun-he commented on a change in pull request #2884:
URL: https://github.com/apache/iceberg/pull/2884#discussion_r678612384
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File path: python/iceberg/parquet/iceberg_to_arrow.py
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@@ -0,0 +1,107 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# 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
+# under the License.
+
+
+import json
+from typing import Callable, Dict
+
+from iceberg.api import Schema
+from iceberg.api.types import NestedField, TypeID
+from iceberg.core import SchemaParser
+import pyarrow as pa
+
+
+ICEBERG_TO_ARROW_MAP: Dict[TypeID, Callable] = {
+ TypeID.BOOLEAN: lambda type_var: pa.lib.bool_(),
+ TypeID.BINARY: lambda type_var: pa.lib.binary(),
+ TypeID.DATE: lambda type_var: pa.lib.date32(),
+ TypeID.DECIMAL: lambda type_var: pa.lib.decimal128(type_var.precision, type_var.scale),
+ TypeID.DOUBLE: lambda type_var: pa.lib.float64(),
+ TypeID.FIXED: lambda type_var: pa.lib.binary(length=type_var.length),
Review comment:
by checking `ArrowSchemaUtil`, it seems not enforcing the length limit
##########
File path: python/iceberg/parquet/iceberg_to_arrow.py
##########
@@ -0,0 +1,107 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# 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
+# under the License.
+
+
+import json
+from typing import Callable, Dict
+
+from iceberg.api import Schema
+from iceberg.api.types import NestedField, TypeID
+from iceberg.core import SchemaParser
+import pyarrow as pa
+
+
+ICEBERG_TO_ARROW_MAP: Dict[TypeID, Callable] = {
+ TypeID.BOOLEAN: lambda type_var: pa.lib.bool_(),
+ TypeID.BINARY: lambda type_var: pa.lib.binary(),
+ TypeID.DATE: lambda type_var: pa.lib.date32(),
+ TypeID.DECIMAL: lambda type_var: pa.lib.decimal128(type_var.precision, type_var.scale),
+ TypeID.DOUBLE: lambda type_var: pa.lib.float64(),
+ TypeID.FIXED: lambda type_var: pa.lib.binary(length=type_var.length),
+ TypeID.FLOAT: lambda type_var: pa.lib.float32(),
+ TypeID.INTEGER: lambda type_var: pa.lib.int32(),
+ TypeID.LIST: lambda type_var: convert_field(type_var),
+ TypeID.LONG: lambda type_var: pa.lib.int64(),
+ TypeID.MAP: lambda type_var: convert_field(type_var),
+ TypeID.STRING: lambda type_var: pa.lib.string(),
+ TypeID.STRUCT: lambda type_var: convert_field(type_var),
+ TypeID.TIME: lambda type_var: pa.lib.time64("us"),
Review comment:
nit: unit ms
##########
File path: python/iceberg/parquet/iceberg_to_arrow.py
##########
@@ -0,0 +1,107 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# 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
+# under the License.
+
+
+import json
+from typing import Callable, Dict
+
+from iceberg.api import Schema
+from iceberg.api.types import NestedField, TypeID
+from iceberg.core import SchemaParser
+import pyarrow as pa
+
+
+ICEBERG_TO_ARROW_MAP: Dict[TypeID, Callable] = {
+ TypeID.BOOLEAN: lambda type_var: pa.lib.bool_(),
+ TypeID.BINARY: lambda type_var: pa.lib.binary(),
+ TypeID.DATE: lambda type_var: pa.lib.date32(),
+ TypeID.DECIMAL: lambda type_var: pa.lib.decimal128(type_var.precision, type_var.scale),
+ TypeID.DOUBLE: lambda type_var: pa.lib.float64(),
+ TypeID.FIXED: lambda type_var: pa.lib.binary(length=type_var.length),
+ TypeID.FLOAT: lambda type_var: pa.lib.float32(),
+ TypeID.INTEGER: lambda type_var: pa.lib.int32(),
+ TypeID.LIST: lambda type_var: convert_field(type_var),
+ TypeID.LONG: lambda type_var: pa.lib.int64(),
+ TypeID.MAP: lambda type_var: convert_field(type_var),
+ TypeID.STRING: lambda type_var: pa.lib.string(),
+ TypeID.STRUCT: lambda type_var: convert_field(type_var),
+ TypeID.TIME: lambda type_var: pa.lib.time64("us"),
+ TypeID.TIMESTAMP: lambda type_var: pa.timestamp("us", tz="UTC" if type_var.adjust_to_utc else None),
+}
Review comment:
seems missing TypeID.UUID
##########
File path: python/iceberg/parquet/iceberg_to_arrow.py
##########
@@ -0,0 +1,107 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# 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
+# under the License.
+
+
+import json
+from typing import Callable, Dict
+
+from iceberg.api import Schema
+from iceberg.api.types import NestedField, TypeID
+from iceberg.core import SchemaParser
+import pyarrow as pa
+
+
+ICEBERG_TO_ARROW_MAP: Dict[TypeID, Callable] = {
+ TypeID.BOOLEAN: lambda type_var: pa.lib.bool_(),
+ TypeID.BINARY: lambda type_var: pa.lib.binary(),
+ TypeID.DATE: lambda type_var: pa.lib.date32(),
+ TypeID.DECIMAL: lambda type_var: pa.lib.decimal128(type_var.precision, type_var.scale),
+ TypeID.DOUBLE: lambda type_var: pa.lib.float64(),
+ TypeID.FIXED: lambda type_var: pa.lib.binary(length=type_var.length),
+ TypeID.FLOAT: lambda type_var: pa.lib.float32(),
+ TypeID.INTEGER: lambda type_var: pa.lib.int32(),
+ TypeID.LIST: lambda type_var: convert_field(type_var),
+ TypeID.LONG: lambda type_var: pa.lib.int64(),
+ TypeID.MAP: lambda type_var: convert_field(type_var),
+ TypeID.STRING: lambda type_var: pa.lib.string(),
+ TypeID.STRUCT: lambda type_var: convert_field(type_var),
+ TypeID.TIME: lambda type_var: pa.lib.time64("us"),
+ TypeID.TIMESTAMP: lambda type_var: pa.timestamp("us", tz="UTC" if type_var.adjust_to_utc else None),
+}
+
+
+def iceberg_to_arrow(iceberg_schema: Schema) -> pa.Schema:
+ """
+ Use an iceberg schema, to create an equivalent arrow schema with intact field_id metadata
+
+ Parameters
+ ----------
+ iceberg_schema : Schema
+ An iceberg schema to map
+
+ Returns
+ -------
+ pyarrow.Schema
+ returns an equivalent pyarrow Schema based on the iceberg schema provided. Performs
+ """
+ arrow_fields = []
+ for field in iceberg_schema.as_struct().fields:
+ arrow_fields.append(convert_field(field))
+
+ return pa.schema(arrow_fields,
+ metadata={b'iceberg.schema': json.dumps(SchemaParser.to_dict(iceberg_schema)).encode("utf-8")})
+
+
+def convert_field(iceberg_field: NestedField) -> pa.Field:
+ """
+ Map an iceberg field to a pyarrow field. Recursively calls itself for nested fields
+ there is currently a limitation in the ability to convert map types since the pyarrow python bindings
+ don't expose a way to set fields for the key and value fields in a map
+
+ Parameters
+ ----------
+ iceberg_field: NestedField
+ An iceberg schema to map
+
+ Returns
+ -------
+ pa.Field
+ returns an equivalent pyarow Field based on the Nested Field.
+ """
+ if iceberg_field.type.is_primitive_type():
+ try:
+ arrow_field = ICEBERG_TO_ARROW_MAP[iceberg_field.type.type_id](iceberg_field.type)
+ except KeyError:
+ raise ValueError(f"Unable to convert {iceberg_field}")
+
+ elif iceberg_field.type.type_id == TypeID.STRUCT:
+ arrow_field = pa.struct([convert_field(field) for field in iceberg_field.type.fields])
+ elif iceberg_field.type.type_id == TypeID.LIST:
+ try:
+ arrow_field = pa.list_(ICEBERG_TO_ARROW_MAP[iceberg_field.type.type_id](iceberg_field.type.element_field))
+ except KeyError:
+ raise ValueError(f"Unable to convert {iceberg_field.type}")
+ elif iceberg_field.type.type_id == TypeID.MAP:
+ raise NotImplementedError("Unable to serialize Map types; python arrow bindings can't pass key/val metadata")
Review comment:
As java ArrowSchemaUtil supports it, wondering if this is python limit?
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