clickhouse-driver 0.2.2

Python driver with native interface for ClickHouse

ClickHouse Python Driver

ClickHouse Python Driver with native (TCP) interface support.

Asynchronous wrapper is available here: https://github.com/mymarilyn/aioch

Features

• External data for query processing.

• Query settings.

• Compression support.

• TLS support.

• Types support:

  • Float32/64

  • [U]Int8/16/32/64/128/256

  • Date/Date32/DateTime(‘timezone’)/DateTime64(‘timezone’)

  • String/FixedString(N)

  • Enum8/16

  • Array(T)

  • Nullable(T)

  • UUID

  • Decimal

  • IPv4/IPv6

  • LowCardinality(T)

  • SimpleAggregateFunction(F, T)

  • Tuple(T1, T2, …)

  • Nested

  • Map(key, value)

• Query progress information.

• Block by block results streaming.

• Reading query profile info.

• Receiving server logs.

• Multiple hosts support.

• Python DB API 2.0 specification support.

• Optional NumPy arrays support.

Documentation

Documentation is available at https://clickhouse-driver.readthedocs.io.

Usage

There are two ways to communicate with server:

• using pure Client;

• using DB API.

Pure Client example:

>>> from clickhouse_driver import Client
>>>
>>> client = Client('localhost')
>>>
>>> client.execute('SHOW TABLES')
[('test',)]
>>> client.execute('DROP TABLE IF EXISTS test')
[]
>>> client.execute('CREATE TABLE test (x Int32) ENGINE = Memory')
[]
>>> client.execute(
...     'INSERT INTO test (x) VALUES',
...     [{'x': 100}]
... )
1
>>> client.execute('INSERT INTO test (x) VALUES', [[200]])
1
>>> client.execute(
...     'INSERT INTO test (x) '
...     'SELECT * FROM system.numbers LIMIT %(limit)s',
...     {'limit': 3}
... )
[]
>>> client.execute('SELECT sum(x) FROM test')
[(303,)]

DB API example:

>>> from clickhouse_driver import connect
>>>
>>> conn = connect('clickhouse://localhost')
>>> cursor = conn.cursor()
>>>
>>> cursor.execute('SHOW TABLES')
>>> cursor.fetchall()
[('test',)]
>>> cursor.execute('DROP TABLE IF EXISTS test')
>>> cursor.fetchall()
[]
>>> cursor.execute('CREATE TABLE test (x Int32) ENGINE = Memory')
>>> cursor.fetchall()
[]
>>> cursor.executemany(
...     'INSERT INTO test (x) VALUES',
...     [{'x': 100}]
... )
>>> cursor.rowcount
1
>>> cursor.executemany('INSERT INTO test (x) VALUES', [[200]])
>>> cursor.rowcount
1
>>> cursor.execute(
...     'INSERT INTO test (x) '
...     'SELECT * FROM system.numbers LIMIT %(limit)s',
...     {'limit': 3}
... )
>>> cursor.rowcount
0
>>> cursor.execute('SELECT sum(x) FROM test')
>>> cursor.fetchall()
[(303,)]

License

ClickHouse Python Driver is distributed under the MIT license.