This is an automated email from the ASF dual-hosted git repository.
mgreber pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/kudu.git
The following commit(s) were added to refs/heads/master by this push:
new 16168018a KUDU-3708 Create Python example for array datatype
16168018a is described below
commit 16168018a4dd6626b966605e02774ee8a156a05d
Author: Gabriella Lotz <[email protected]>
AuthorDate: Mon Oct 13 15:27:33 2025 +0200
KUDU-3708 Create Python example for array datatype
Add a Python client example demonstrating array data type operations
(insert, scan, update, delete), similar to the C++ example (95abb8d).
The example shows working with arrays containing NULL elements, empty
arrays, and arrays of varying lengths.
Also updated test-python-examples.sh to run the new example in CI
and updated the README to document it.
Change-Id: I4a84ee9731efdc802673bb964d358b07648b3fae
Reviewed-on: http://gerrit.cloudera.org:8080/23531
Reviewed-by: Zoltan Martonka <[email protected]>
Reviewed-by: Marton Greber <[email protected]>
Tested-by: Marton Greber <[email protected]>
---
examples/python/basic-python-example/README.md | 19 +-
.../python/basic-python-example/array_example.py | 214 +++++++++++++++++++++
python/test-python-examples.sh | 9 +
3 files changed, 238 insertions(+), 4 deletions(-)
diff --git a/examples/python/basic-python-example/README.md
b/examples/python/basic-python-example/README.md
index d94441cb0..dca0d05ef 100644
--- a/examples/python/basic-python-example/README.md
+++ b/examples/python/basic-python-example/README.md
@@ -12,9 +12,13 @@ See the License for the specific language governing
permissions and
limitations under the License.
-->
-# Basic Kudu-Python example
-This is a very basic example of usage for the Kudu Python client.
-It demonstrates much of the standard capabilities within the client.
+# Basic Kudu-Python examples
+This directory contains basic examples of usage for the Kudu Python client.
+These examples demonstrate the standard capabilities within the client:
+
+- **basic_example.py**: Basic CRUD operations (create, read, update, delete)
+- **non_unique_primary_key.py**: Working with non-unique primary keys and
auto-incrementing columns
+- **array_example.py**: Using array data types with insert, scan, update, and
delete operations
## To install the Python client
@@ -53,7 +57,14 @@ export DYLD_LIBRARY_PATH=$KUDU_HOME/build/latest/lib/exported
pip install kudu-python
```
-## Running the example
+## Running the examples
```
+# Run the basic example
python basic_example.py --masters master1.address --ports 7051
+
+# Run the non-unique primary key example
+python non_unique_primary_key.py --masters master1.address --ports 7051
+
+# Run the array data type example
+python array_example.py --masters master1.address --ports 7051
```
diff --git a/examples/python/basic-python-example/array_example.py
b/examples/python/basic-python-example/array_example.py
new file mode 100644
index 000000000..77f3a78dc
--- /dev/null
+++ b/examples/python/basic-python-example/array_example.py
@@ -0,0 +1,214 @@
+# 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 argparse
+
+import kudu
+from kudu.client import Partitioning
+
+
+def create_schema():
+ """
+ Create a schema for a table with array columns.
+
+ Similar to CreateSchema() in the C++ example, this creates a schema with:
+ - A primary key column (key)
+ - A regular INT32 column (int_val)
+ - Array columns for INT64, STRING, and DOUBLE types
+ """
+ builder = kudu.schema_builder()
+ builder.add_column('key').type(kudu.int32).nullable(False).primary_key()
+ builder.add_column('int_val', type_=kudu.int32, nullable=False)
+
+ # Add array columns for different data types.
+ # Array of INT64 values.
+ builder.add_column('arr_int64').nested_type(kudu.array_type(kudu.int64))
+ # Array of STRING values.
+ builder.add_column('arr_string').nested_type(kudu.array_type(kudu.string))
+ # Array of DOUBLE values.
+ builder.add_column('arr_double').nested_type(kudu.array_type(kudu.double))
+
+ return builder.build()
+
+
+def insert_rows(table, session, num_rows):
+ """
+ Insert rows with array data into the table.
+
+ Arrays can contain None to represent NULL values, and can have
+ different lengths.
+ """
+ for i in range(num_rows):
+ op = table.new_insert({'key': i, 'int_val': i * 2})
+ # Array with three elements, two non-nulls and one null in the middle.
+ op['arr_int64'] = [i * 6, None, i * 7]
+ op['arr_string'] = ['row_{0}'.format(i), 'data_{0}'.format(i), None]
+ # Arrays can have different lengths.
+ if i % 2 == 0:
+ op['arr_double'] = [i * 1.1, i * 2.2, i * 3.3]
+ else:
+ op['arr_double'] = [i * 5.5]
+ session.apply(op)
+
+ # Flush write operations, if failures occur, print them and exit.
+ try:
+ session.flush()
+ except kudu.KuduBadStatus:
+ print(session.get_pending_errors())
+ raise
+
+
+def scan_rows(table, lower_bound=None, upper_bound=None, limit=None):
+ """
+ Scan and print rows from the table.
+
+ Optionally filter by key range [lower_bound, upper_bound] and limit
+ the number of rows printed.
+ """
+ scanner = table.scanner()
+
+ # Add predicates if bounds are specified.
+ if lower_bound is not None:
+ scanner.add_predicate(table['key'] >= lower_bound)
+ if upper_bound is not None:
+ scanner.add_predicate(table['key'] <= upper_bound)
+
+ scanner.open()
+ row_count = 0
+ while scanner.has_more_rows():
+ batch = scanner.read_next_batch_tuples()
+ for row in batch:
+ if limit is None or row_count < limit:
+ print('(key: {0}, int_val: {1}, arr_int64: {2}, arr_string: {3},
arr_double: {4})'.format(
+ row[0], row[1], row[2], row[3], row[4]))
+ row_count += 1
+
+ return row_count
+
+
+def update_row(table, session, key, int_val, arr_int64, arr_string,
arr_double):
+ """Update a row with new array values."""
+ op = table.new_update({'key': key, 'int_val': int_val})
+ op['arr_int64'] = arr_int64
+ op['arr_string'] = arr_string
+ op['arr_double'] = arr_double
+ session.apply(op)
+
+ try:
+ session.flush()
+ except kudu.KuduBadStatus:
+ print(session.get_pending_errors())
+ raise
+
+
+def delete_rows(table, session, keys):
+ """Delete rows with the specified keys."""
+ for key in keys:
+ op = table.new_delete({'key': key})
+ session.apply(op)
+
+ try:
+ session.flush()
+ except kudu.KuduBadStatus:
+ print(session.get_pending_errors())
+ raise
+
+
+# Parse arguments.
+parser = argparse.ArgumentParser(description='Array Data Type Example for Kudu
Python.')
+parser.add_argument('--masters', '-m', nargs='+', default='localhost',
+ help='The master address(es) to connect to Kudu.')
+parser.add_argument('--ports', '-p', nargs='+', default='7051',
+ help='The master server port(s) to connect to Kudu.')
+args = parser.parse_args()
+
+# Connect to Kudu master server(s).
+client = kudu.connect(host=args.masters, port=args.ports)
+
+# Create a schema with array columns.
+schema = create_schema()
+
+# Define the partitioning schema.
+partitioning = Partitioning().add_hash_partitions(column_names=['key'],
num_buckets=3)
+
+# Delete table if it already exists.
+table_name = 'python-array-example'
+if client.table_exists(table_name):
+ client.delete_table(table_name)
+
+# Create a new table.
+client.create_table(table_name, schema, partitioning)
+
+# Open a table.
+table = client.table(table_name)
+
+# Create a new session so that we can apply write operations.
+session = client.new_session()
+
+# Insert rows with array data.
+insert_rows(table, session, 10)
+
+# Scan and read array data.
+print('Scanning first 3 rows:')
+total = scan_rows(table, limit=3)
+print('Total rows: {0}\n'.format(total))
+
+# Scan with predicates.
+print('Scanning rows with key >= 5 AND key <= 7:')
+scan_rows(table, lower_bound=5, upper_bound=7)
+print('')
+
+# Update a row with new array data (different length arrays).
+update_row(table, session, key=3, int_val=999,
+ arr_int64=[100, 200, 300, 400],
+ arr_string=['updated', 'data'],
+ arr_double=[99.9])
+
+print('Updated row (key=3):')
+scan_rows(table, lower_bound=3, upper_bound=3)
+print('')
+
+# Insert a row with empty arrays.
+op = table.new_insert({'key': 100, 'int_val': 0})
+op['arr_int64'] = []
+op['arr_string'] = []
+op['arr_double'] = []
+session.apply(op)
+
+try:
+ session.flush()
+except kudu.KuduBadStatus:
+ print(session.get_pending_errors())
+ raise
+
+print('Row with empty arrays (key=100):')
+scan_rows(table, lower_bound=100, upper_bound=100)
+print('')
+
+# Delete specific rows.
+delete_rows(table, session, [5, 6, 7])
+
+# Verify deletion.
+print('Remaining keys in range [4-8] after deletion:')
+scanner = table.scanner()
+scanner.add_predicate(table['key'] >= 4)
+scanner.add_predicate(table['key'] <= 8)
+remaining_keys = [row[0] for row in scanner.open().read_all_tuples()]
+print(sorted(remaining_keys))
+
+# Clean up - delete the table.
+client.delete_table(table_name)
diff --git a/python/test-python-examples.sh b/python/test-python-examples.sh
index c5ec2b80e..1acfda4b8 100755
--- a/python/test-python-examples.sh
+++ b/python/test-python-examples.sh
@@ -35,6 +35,7 @@
VALID_EXAMPLES=(
"basic_example.py"
"non_unique_primary_key.py"
+ "array_example.py"
)
PYTHON_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")"; pwd)
@@ -96,6 +97,14 @@ test_example() {
exit_error "non_unique_primary_key.py failed with $python_version"
fi
;;
+ array_example.py)
+ echo "Testing array_example.py..."
+ if ! "$python_version"
"$EXAMPLES_DIR/basic-python-example/array_example.py" \
+ --masters $LOCALHOST_IP \
+ --ports $MASTER_RPC_PORT ; then
+ exit_error "array_example.py failed with $python_version"
+ fi
+ ;;
*)
exit_error "Unknown example script: $example_script"
;;
