Add an example of how to run async

examples/run_async.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python -u
+
+import asyncio
+from datetime import datetime
+
+import clickhouse_connect
+
+QUERIES = 100
+SEMAPHORE = 10
+
+clickhouse_connect.common.set_setting("autogenerate_session_id", False)
+
+
+class AsyncRunner:
+    def __init__(self, **client_params):
+        self.client = clickhouse_connect.create_client(**client_params)
+        self.query_count = 0
+        self.row_count = 0
+
+    async def run_query(self, query: str, num: int):
+        self.query_count += 1
+
+        def read_data():
+            return self.client.query(query).result_set
+
+        result_set = await asyncio.to_thread(read_data)
+        self.row_count += len(result_set)
+        print(f"completed query {num}")
+        return result_set
+
+
+async def concurrent_queries():
+    test_query = ("SELECT * FROM generateRandom('a Array(Int8), d Decimal32(4)," +
+                  " c Tuple(DateTime64(3), UUID)', 1, 10, 2) LIMIT 200000")
+    runner = AsyncRunner()
+
+    print(datetime.now())
+
+    async def semaphore_wrapper(sm: asyncio.Semaphore, num: int):
+        async with sm:
+            await runner.run_query(test_query, num)
+
+    semaphore = asyncio.Semaphore(SEMAPHORE)
+    await asyncio.gather(*[semaphore_wrapper(semaphore, num) for num in range(QUERIES)])
+    print(f"{datetime.now()}  query_count: {runner.query_count}  row_count: {runner.row_count}")
+
+
+loop = asyncio.get_event_loop()
+try:
+    loop.run_until_complete(concurrent_queries())
+finally:
+    loop.close()