Standalone activity

README.md

@@ -55,6 +55,8 @@ Some examples require extra dependencies. See each sample's directory for specif
   * [hello_search_attributes](hello/hello_search_attributes.py) - Start workflow with search attributes then change
     while running.
   * [hello_signal](hello/hello_signal.py) - Send signals to a workflow.
+  * [hello standalone activity](hello/hello_standalone_activity.py) - Execute an activity from outside of a workflow.
+  * [hello update](hello/hello_update.py) - Send a request to and a response from a client to a workflow execution.
 <!-- Keep this list in alphabetical order -->
 * [activity_worker](activity_worker) - Use Python activities from a workflow in another language.
 * [batch_sliding_window](batch_sliding_window) - Batch processing with a sliding window of child workflows.

hello/README.md

@@ -44,7 +44,8 @@ Replace `hello/hello_activity.py` in the command with any other example filename
 * [hello_search_attributes](hello_search_attributes.py) - Start workflow with search attributes then change while
   running.
 * [hello_signal](hello_signal.py) - Send signals to a workflow.
-* [hello_update](hello_update.py) - Send a request to and a response from a client to a workflow execution.
+* [hello standalone activity](hello_standalone_activity.py) - Execute an activity from outside of a workflow.
+* [hello_update](hello_update.py) - **Send a request to and a response from a client to a workflow execution.**
 
 Note: To enable the workflow update, set the `frontend.enableUpdateWorkflowExecution` dynamic config value to true.
 

hello/hello_standalone_activity.py

@@ -0,0 +1,77 @@
+import asyncio
+from dataclasses import dataclass
+from datetime import timedelta
+
+from temporalio import activity
+from temporalio.client import Client
+from temporalio.envconfig import ClientConfig
+from temporalio.worker import Worker
+
+# This sample is very similar to hello_activity.py. The difference is that whereas in
+# hello_activity.py the activity is orchestrated by a workflow, in this sample the activity is
+# executed directly by a client ("standalone activity").
+
+
+@dataclass
+class ComposeGreetingInput:
+    greeting: str
+    name: str
+
+
+# This is just a normal activity. You could invoke it from a workflow but, in this sample, we are
+# invoking it directly as a standalone activity.
+@activity.defn
+async def compose_greeting(input: ComposeGreetingInput) -> str:
+    activity.logger.info("Running activity with parameter %s" % input)
+    return f"{input.greeting}, {input.name}!"
+
+
+async def my_client_code(client: Client):
+    # client.execute_activity starts the activity, and then uses a long-poll to wait for the
+    # activity to be completed by the worker.
+    result = await client.execute_activity(
+        compose_greeting,
+        args=[ComposeGreetingInput("Hello", "World")],
+        id="my-standalone-activity-id",
+        task_queue="hello-standalone-activity-task-queue",
+        start_to_close_timeout=timedelta(seconds=10),
+    )
+    print(f"Activity result: {result}")
+
+    activities = client.list_activities(
+        query="TaskQueue = 'hello-standalone-activity-task-queue'"
+    )
+    print("ListActivity results:")
+    async for info in activities:
+        print(
+            f"\tActivityID: {info.activity_id}, Type: {info.activity_type}, Status: {info.status}"
+        )
+
+    count_result = await client.count_activities(
+        query="TaskQueue = 'hello-standalone-activity-task-queue'"
+    )
+    print(f"Total activities: {count_result.count}")
+
+
+async def main():
+    # Uncomment the lines below to see logging output
+    # import logging
+    # logging.basicConfig(level=logging.INFO)
+
+    config = ClientConfig.load_client_connect_config()
+    config.setdefault("target_host", "localhost:7233")
+
+    client = await Client.connect(**config)
+
+    # Run a worker for the activity
+    async with Worker(
+        client,
+        task_queue="hello-standalone-activity-task-queue",
+        activities=[compose_greeting],
+    ):
+        # While the worker is running, use the client to execute the activity.
+        await my_client_code(client)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())