Python: Add partition field

python/src/iceberg/partitioning.py

@@ -0,0 +1,57 @@
+# 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.
+from iceberg.transforms import Transform
+
+
+class PartitionField:
+    """
+    PartitionField is a single element with name and unique id,
+    It represents how one partition value is derived from the source column via transformation
+    """
+
+    def __init__(self, source_id: int, field_id: int, transform: Transform, name: str):
+        self._source_id = source_id
+        self._field_id = field_id
+        self._transform = transform
+        self._name = name
+
+    @property
+    def source_id(self) -> int:
+        return self._source_id
+
+    @property
+    def field_id(self) -> int:
+        return self._field_id
+
+    @property
+    def name(self) -> str:
+        return self._name
+
+    @property
+    def transform(self) -> Transform:
+        return self._transform
+
+    def __eq__(self, other):
+        return self.field_id == other.field_id
+
+    def __str__(self):
+        return f"{self.field_id}: {self.name}: {self.transform}: ({self.source_id})"
+
+    def __repr__(self):
+        return (
+            f"PartitionField(field_id={self.field_id}, name={self.name}, transform={self._transform}, source_id={self.source_id})"
+        )

python/tests/test_partitioning.py

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+# 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.
+
+from iceberg.partitioning import PartitionField
+from iceberg.transforms import bucket
+from iceberg.types import IntegerType
+
+
+def test_partition_field_init():
+    bucket_transform = bucket(IntegerType(), 100)
+    partition_field = PartitionField(3, 1, bucket_transform, "id")
+
+    assert partition_field.source_id == 3
+    assert partition_field.field_id == 1
+    assert partition_field.transform == bucket_transform
+    assert partition_field.name == "id"
+    assert partition_field == partition_field
+    assert str(partition_field) == f"1: id: bucket[100]: (3)"
+    assert repr(partition_field) == f"PartitionField(field_id=1, name=id, transform=bucket[100], source_id=3)"