dev-718 / python-clickhouse_driver

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)
  • Bool
  • 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.