Merge branch 'python-example' into 'master'

feat(python): add python example with asyncpg

See merge request !8

picodata-python-example/README.md

+# Working with Picodata using Python asyncpg
+
+## Requirements
+
+- Python 3.9
+- [asyncpg](https://pypi.org/project/asyncpg/)
+
+## Running this example
+
+1. Install dependencies
+
+``` sh
+pip install asyncpg
+```
+
+2. Run Picodata cluster
+
+``` sh
+docker-compose up -d
+```
+
+3. Run `picodata_example.py`
+
+``` sh
+python picodata_example.py
+```
+
+In case of successful run you should see logs like the following in your console:
+
+``` sh
+table create
+delete ok:  DELETE 0
+insert ok INSERT 0 1
+result:  <Record id=1 item='test'>
+```

picodata-python-example/docker-compose.yml

+version: '3.9'
+
+services:
+  picodata-1-1:
+    image: docker.binary.picodata.io/picodata:25.1.1-distroless
+    container_name: picodata-1-1
+    hostname: picodata-1-1
+    environment:
+      PICODATA_PEER: picodata-1-1:3301
+      PICODATA_LISTEN: picodata-1-1:3301
+      PICODATA_INSTANCE_DIR: /pico/data/picodata-1-1
+      PICODATA_ADVERTISE: picodata-1-1:3301
+      PICODATA_FAILURE_DOMAIN: HOST=picodata-1
+      PICODATA_INIT_REPLICATION_FACTOR: 2
+      PICODATA_HTTP_LISTEN: picodata-1-1:8001
+      PICODATA_PG_LISTEN: picodata-1-1:5432
+      PICODATA_ADMIN_PASSWORD: T0psecret
+      PICODATA_LOG_LEVEL: info
+    volumes:
+      - $PWD/tmp:/pico
+    ports:
+      - "13301:3301"
+      - "18301:8001"
+      - "55432:5432"
+
+  picodata-1-2:
+    image: docker.binary.picodata.io/picodata:25.1.1-distroless
+    container_name: picodata-1-2
+    hostname: picodata-1-2
+    environment:
+      PICODATA_PEER: picodata-1-1:3301
+      PICODATA_LISTEN: picodata-1-2:3301
+      PICODATA_INSTANCE_DIR: /pico/data/picodata-1-2
+      PICODATA_ADVERTISE: picodata-1-2:3301
+      PICODATA_FAILURE_DOMAIN: HOST=picodata-1
+      PICODATA_INIT_REPLICATION_FACTOR: 2
+      PICODATA_HTTP_LISTEN: picodata-1-2:8001
+      PICODATA_LOG_LEVEL: info
+    volumes:
+      - $PWD/tmp:/pico
+    ports:
+      - "13302:3301"
+      - "18302:8001"
+
+  picodata-2-1:
+    image: docker.binary.picodata.io/picodata:25.1.1-distroless
+    container_name: picodata-2-1
+    hostname: picodata-2-1
+    environment:
+      PICODATA_PEER: picodata-1-1:3301
+      PICODATA_LISTEN: picodata-2-1:3301
+      PICODATA_INSTANCE_DIR: /pico/data/picodata-2-1
+      PICODATA_ADVERTISE: picodata-2-1:3301
+      PICODATA_FAILURE_DOMAIN: HOST=picodata-2
+      PICODATA_INIT_REPLICATION_FACTOR: 2
+      PICODATA_HTTP_LISTEN: picodata-2-1:8001
+      PICODATA_LOG_LEVEL: info
+    volumes:
+      - $PWD/tmp:/pico
+    ports:
+      - "13303:3301"
+      - "18303:8001"
+
+  picodata-2-2:
+    image: docker.binary.picodata.io/picodata:25.1.1-distroless
+    container_name: picodata-2-2
+    hostname: picodata-2-2
+    environment:
+      PICODATA_PEER: picodata-1-1:3301
+      PICODATA_LISTEN: picodata-2-2:3301
+      PICODATA_INSTANCE_DIR: /pico/data/picodata-2-2
+      PICODATA_ADVERTISE: picodata-2-2:3301
+      PICODATA_FAILURE_DOMAIN: HOST=picodata-2
+      PICODATA_INIT_REPLICATION_FACTOR: 2
+      PICODATA_HTTP_LISTEN: picodata-2-2:8001
+      PICODATA_LOG_LEVEL: info
+    volumes:
+      - $PWD/tmp:/pico
+    ports:
+      - "13304:3301"
+      - "18304:8001"

picodata-python-example/picodata_example.py

+#!/usr/bin/env python3
+
+import asyncio
+import asyncpg
+
+async def main():
+    conn = await asyncpg.connect('postgresql://admin:T0psecret@localhost:55432')
+
+    await conn.execute('''
+        CREATE TABLE "warehouse" (id INTEGER NOT NULL, item TEXT NOT NULL, PRIMARY KEY (id)) USING memtx DISTRIBUTED BY (id) OPTION (TIMEOUT = 3.0);
+    ''')
+    print("table create")
+
+    res = await conn.execute('DELETE FROM \"warehouse\";')
+    print("delete ok: ", res)
+
+    res = await conn.execute('INSERT INTO \"warehouse\" VALUES ($1::int, $2::varchar)', 1, "test")
+    print("insert ok", res)
+
+    res = await conn.fetchrow('SELECT * FROM warehouse WHERE id = $1::int', 1)
+    print("result: ", res)
+
+    # Close the connection.
+    await conn.close()
+
+asyncio.run(main())