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ClickHouse Python Driver

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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.