[DAE-121] Adding custom get_partition_values method (#50)

docs/source/getstarted.md

@@ -34,6 +34,8 @@ Click on the following links to open the [examples](https://github.com/quintoand
 
 **[#8 Bulk drop partitions values from a table](https://github.com/quintoandar/hive-metastore-client/blob/main/examples/bulk_drop_partitions.py)**
 
+**[#9 Get partition values from a table](https://github.com/quintoandar/hive-metastore-client/blob/main/examples/get_partition_values_from_table.py)**
+
 ## Available methods
 
 You can see all the Hive Metastore server available methods by looking at the 
@@ -50,4 +52,5 @@ the [`HiveMetastoreClient`](https://github.com/quintoandar/hive-metastore-client
 - [`create_external_table`](https://hive-metastore-client.readthedocs.io/en/latest/hive_metastore_client.html#hive_metastore_client.hive_metastore_client.HiveMetastoreClient.create_external_table)
 - [`get_partition_keys_objects`](https://hive-metastore-client.readthedocs.io/en/latest/hive_metastore_client.html#hive_metastore_client.hive_metastore_client.HiveMetastoreClient.get_partition_keys_objects)
 - [`get_partition_keys_names`](https://hive-metastore-client.readthedocs.io/en/latest/hive_metastore_client.html#hive_metastore_client.hive_metastore_client.HiveMetastoreClient.get_partition_keys_names)
-- [`bulk_drop_partitions`](https://hive-metastore-client.readthedocs.io/en/latest/hive_metastore_client.html#hive_metastore_client.hive_metastore_client.HiveMetastoreClient.bulk_drop_partitions)
+- [`bulk_drop_partitions`](https://hive-metastore-client.readthedocs.io/en/latest/hive_metastore_client.html#hive_metastore_client.hive_metastore_client.HiveMetastoreClient.bulk_drop_partitions)
+- [`get_partition_values_from_table`](https://hive-metastore-client.readthedocs.io/en/latest/hive_metastore_client.html#hive_metastore_client.hive_metastore_client.HiveMetastoreClient.get_partition_values_from_table)

examples/get_partition_values_from_table.py

@@ -0,0 +1,13 @@
+from hive_metastore_client import HiveMetastoreClient
+
+HIVE_HOST = "<ADD_HIVE_HOST_HERE>"
+HIVE_PORT = 9083
+
+DATABASE_NAME = "database_name"
+TABLE_NAME = "table_name"
+
+with HiveMetastoreClient(HIVE_HOST, HIVE_PORT) as hive_client:
+    # Getting partition values as a list from specified table
+    return_value = hive_client.get_partition_values_from_table(
+        DATABASE_NAME, TABLE_NAME
+    )

hive_metastore_client/hive_metastore_client.py

@@ -15,6 +15,7 @@
     Database,
     AlreadyExistsException,
     Table,
+    PartitionValuesRequest,
     NoSuchObjectException,
 )
 
@@ -296,3 +297,31 @@ def bulk_drop_partitions(
                 f"{partitions_not_dropped}, msg=Some partition values were not "
                 "dropped because they do not exist."
             )
+
+    def get_partition_values_from_table(
+        self, db_name: str, table_name: str
+    ) -> List[List[str]]:
+        """
+        Gets the partition names from a table.
+
+        It automatically fetches the table's partition keys.
+
+        An empty list will be returned when no table is found or
+        when the table has no partitions.
+
+        :param db_name: database name where the table is at
+        :param table_name: table name which the partitions belong to
+        """
+        partition_values_response = self.get_partition_values(
+            PartitionValuesRequest(
+                dbName=db_name,
+                tblName=table_name,
+                partitionKeys=self.get_partition_keys_objects(
+                    db_name=db_name, table_name=table_name
+                ),
+            )
+        )
+
+        return [
+            partition.row for partition in partition_values_response.partitionValues
+        ]

tests/unit/hive_metastore_client/test_hive_metastore_client.py

@@ -11,6 +11,7 @@
     FieldSchema,
     NoSuchObjectException,
     AlreadyExistsException,
+    PartitionValuesRequest,
 )
 
 
@@ -472,3 +473,48 @@ def test_bulk_drop_partitions_with_errors(
             )
 
         assert mock_drop_partition.call_count == len(partition_list)
+
+    @mock.patch.object(HiveMetastoreClient, "get_partition_values", return_value=[])
+    @mock.patch.object(
+        HiveMetastoreClient, "get_partition_keys_objects", return_value=[]
+    )
+    def test_get_partition_values_from_table_with_partitioned_table(
+        self,
+        mocked_get_partition_keys_objects,
+        mocked_get_partition_values,
+        hive_metastore_client,
+    ):
+        # arrange
+        table_name = "table_name"
+        database_name = "database_name"
+        mocked_partition_values_response = Mock()
+        mocked_partition_values = []
+
+        mocked_partition_values_partition_a = Mock()
+        mocked_partition_values_partition_a.row = ["partition_a"]
+        mocked_partition_values.append(mocked_partition_values_partition_a)
+
+        mocked_partition_values_partition_b = Mock()
+        mocked_partition_values_partition_b.row = ["partition_b"]
+        mocked_partition_values.append(mocked_partition_values_partition_b)
+
+        mocked_partition_values_response.partitionValues = mocked_partition_values
+        mocked_get_partition_values.return_value = mocked_partition_values_response
+        expected_partition_values_request = PartitionValuesRequest(
+            dbName=database_name, tblName=table_name, partitionKeys=[],
+        )
+        expected_return = [["partition_a"], ["partition_b"]]
+
+        # act
+        returned_value = hive_metastore_client.get_partition_values_from_table(
+            database_name, table_name
+        )
+
+        # assert
+        assert returned_value == expected_return
+        mocked_get_partition_keys_objects.assert_called_once_with(
+            db_name=database_name, table_name=table_name
+        )
+        mocked_get_partition_values.assert_called_once_with(
+            expected_partition_values_request
+        )