An error occurs "TypeError: 'coroutine' object is not subscriptable" while trying to upload a file via IoT HUB

Question

Hi, I am trying to upload a file from a local laptop (Windows 10, python 3.8.5), but the file cannot be uploaded somehow.

I just copied and pasted the following official source code and executed.

https://learn.microsoft.com/en-us/azure/iot-hub/file-upload-python

As the title mentioned, the appearing error is "TypeError: 'coroutine' object is not subscriptable" .

Since I continuously received warnings saying "RuntimeWarning: coroutine 'execute_patch_for_async.<locals>.connect' was never awaited device_client.connect()", I believe it is something related to asyncio library.

Any solutions?

Answer 1

It actually worked after chaging the original code as follows (the rest is the same):

async def run_sample(device_client):
    # Connect the client
    await device_client.connect()

    # Get the storage info for the blob
    blob_name = os.path.basename(PATH_TO_FILE)
    storage_info = await device_client.get_storage_info_for_blob(blob_name)

    # Upload to blob
    success, result = store_blob(storage_info, PATH_TO_FILE)

    if success == True:
        print("Upload succeeded. Result is: \n")
        print(result)
        print()

        await device_client.notify_blob_upload_status(
            storage_info["correlationId"], True, 200, "OK: {}".format(PATH_TO_FILE)
        )

    else:
        # If the upload was not successful, the result is the exception object
        print("Upload failed. Exception is: \n")
        print(result)
        print()

        await device_client.notify_blob_upload_status(
            storage_info["correlationId"], False, result.status_code, str(result)
        )

async def main():
    device_client = IoTHubDeviceClient.create_from_connection_string(CONNECTION_STRING)

    try:
        print("IoT Hub file upload sample, press Ctrl-C to exit")
        await run_sample(device_client)
    except KeyboardInterrupt:
        print("IoTHubDeviceClient sample stopped")
    finally:
        # Graceful exit
        await device_client.shutdown()


if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    try:
        loop.run_until_complete(main())
    finally:
        loop.close()
    
-cannot delete the following scripts, but please ignore it--
    try:
        print("IoT Hub file upload sample, press Ctrl-C to exit")
        await run_sample(device_client)
    except KeyboardInterrupt:
        print("IoTHubDeviceClient sample stopped")
    finally:
        # Graceful exit
        await device_client.shutdown()


if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    try:
        loop.run_until_complete(main())
    finally:
        loop.close()