Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/long2ice/asynch

An asyncio ClickHouse Python Driver with native (TCP) interface support.
https://github.com/long2ice/asynch

asyncio clickhouse driver native yandex

Last synced: 4 days ago
JSON representation

An asyncio ClickHouse Python Driver with native (TCP) interface support.

Awesome Lists containing this project

README

        

# asynch

![pypi](https://img.shields.io/pypi/v/asynch.svg?style=flat)
![license](https://img.shields.io/github/license/long2ice/asynch)
![workflows](https://github.com/long2ice/asynch/workflows/pypi/badge.svg)
![workflows](https://github.com/long2ice/asynch/workflows/ci/badge.svg)

## Introduction

`asynch` is an asynchronous ClickHouse Python driver with native TCP interface support, which reuses most of [clickhouse-driver](https://github.com/mymarilyn/clickhouse-driver) features and complies with [PEP249](https://www.python.org/dev/peps/pep-0249/).

## Installation

```shell
> pip install asynch
```

If you want to install [`clickhouse-cityhash`](https://pypi.org/project/clickhouse-cityhash/) to enable transport compression

```shell
> pip install asynch[compression]
```

## Usage

Basically, a connection to a ClickHouse server can be established in two ways:

1. with a DSN string, e.g., `clickhouse://[user:password]@host:port/database`;

```python
from asynch import connect

# connecting with a DSN string
async def connect_database():
conn = await connect(
dsn = "clickhouse://ch_user:P@55w0rD:@127.0.0.1:9000/chdb",
)
```

2. with separately given connection/DSN parameters: `user` (optional), `password` (optional), `host`, `port`, `database`.

```python
from asynch import connect

# connecting with DSN parameters
async def connect_database():
conn = await connect(
user = "ch_user",
password = "P@55w0rD",
host = "127.0.0.1",
port = 9000,
database = "chdb",
)
```

If a DSN string is given, it takes priority over any specified connection parameter.

Create a database and a table by executing SQL statements via an instance of the `Cursor` class (here its child `DictCursor` class) acquired from an instance of the `Connection` class.

```python
async def create_table(conn: Connection):
async with conn.cursor(cursor=DictCursor) as cursor:
await cursor.execute("CREATE DATABASE IF NOT EXISTS test")
await cursor.execute("""
CREATE TABLE if not exists test.asynch
(
`id` Int32,
`decimal` Decimal(10, 2),
`date` Date,
`datetime` DateTime,
`float` Float32,
`uuid` UUID,
`string` String,
`ipv4` IPv4,
`ipv6` IPv6
)
ENGINE = MergeTree
ORDER BY id
"""
)
```

Fetching one row from an executed SQL statement:

```python
async def fetchone(conn: Connection):
# by default, an instance of the `Cursor` class
async with conn.cursor() as cursor:
await cursor.execute("SELECT 1")
ret = await cursor.fetchone()
assert ret == (1,)
```

Fetching all the rows from an executed SQL statement:

```python
async def fetchall():
async with conn.cursor() as cursor:
await cursor.execute("SELECT 1")
ret = await cursor.fetchall()
assert ret == [(1,)]
```

Using an instance of the `DictCursor` class to get results as a sequence of `dict`ionaries representing the rows of an executed SQL query:

```python
async def dict_cursor():
async with conn.cursor(cursor=DictCursor) as cursor:
await cursor.execute("SELECT 1")
ret = await cursor.fetchall()
assert ret == [{"1": 1}]
```

Inserting data with `dict`s via a `DictCursor` instance:

```python
from asynch.cursors import DictCursor

async def insert_dict():
async with conn.cursor(cursor=DictCursor) as cursor:
ret = await cursor.execute(
"""INSERT INTO test.asynch(id,decimal,date,datetime,float,uuid,string,ipv4,ipv6) VALUES""",
[
{
"id": 1,
"decimal": 1,
"date": "2020-08-08",
"datetime": "2020-08-08 00:00:00",
"float": 1,
"uuid": "59e182c4-545d-4f30-8b32-cefea2d0d5ba",
"string": "1",
"ipv4": "0.0.0.0",
"ipv6": "::",
}
],
)
assert ret == 1
```

Inserting data with `tuple`s:

```python
async def insert_tuple():
async with conn.cursor(cursor=DictCursor) as cursor:
ret = await cursor.execute(
"""INSERT INTO test.asynch(id,decimal,date,datetime,float,uuid,string,ipv4,ipv6) VALUES""",
[
(
1,
1,
"2020-08-08",
"2020-08-08 00:00:00",
1,
"59e182c4-545d-4f30-8b32-cefea2d0d5ba",
"1",
"0.0.0.0",
"::",
)
],
)
assert ret == 1
```

### Connection Pool

Before the v0.2.4:

```python
async def use_pool():
pool = await asynch.create_pool()
async with pool.acquire() as conn:
async with conn.cursor() as cursor:
await cursor.execute("SELECT 1")
ret = await cursor.fetchone()
assert ret == (1,)
pool.close()
await pool.wait_closed()
```

Since the v0.2.5:

```python
async def use_pool():
# init a Pool and fill it with `minsize` opened connections
async with Pool(minsize=1, maxsize=2) as pool:
# acquire a connection from the pool
async with pool.connection() as conn:
async with conn.cursor() as cursor:
await cursor.execute("SELECT 1")
ret = await cursor.fetchone()
assert ret == (1,)
```

## ThanksTo

- [clickhouse-driver](https://github.com/mymarilyn/clickhouse-driver), ClickHouse Python Driver with native interface support.

## License

This project is licensed under the [Apache-2.0](https://github.com/long2ice/asynch/blob/master/LICENSE) License.