services: iot-hub platforms: python author: msonecode

How to get started for using IoT Hub REST API in Python

About this sample

The sample project demonstrates how to get started for using IoT Hub REST API in Python.

The REST APIs for IoT Hub offer programmatic access to the device and messaging services, as well as the resource provider, in IoT Hub. You can access messaging services within an IoT service running in Azure, or you can directly over the Internet from any application that can send an HTTP/HTTPS request and receive an HTTP/HTTPS response. You can visit the IoT Hub REST API references on Microsoft Azure official site to learn more about these APIs, requirements, parameters, request and response via HTTP methods.

In the sample project, steps at below will be proivded for us to get started.

1. Create an IoT Hub through Azure Portal.
2. Get the connection information from the settings on Azure portal.
3. A simple Python script shows how to create a device identity at the IoT Hub, list all registered device identities from IoT Hub.
4. A simple Python script shows how to send messages from the simulated device application to IoT Hub.

Create an IoT Hub through Azure Portal

To do this, refer to the article Create an IoT Hub through Azure Portal.

Get the connection information

• Getting the IoT Hub Hostname

  Copy the IoT Hub Hostname at the dashboard.

  

• Getting the Shared access key and Connection string of the policy

  Click the Key button to show the Shared access policies, then select one policy, then copy the Shared access key and Connection string.

  

  

Building the sample

You can use Eclipse with PyDev Plugin to import the sample project.

Preparation

• Install the Python package requests via command pip install requests
• Download Eclipse

• Install PyDev plugin via Eclipse Marketplace, click Help -> Eclipse Marketplace, then input PyDev in the search box and enter, then click the install button and follow the tips to install until Finish and restart Eclipse.

  

  

Import the sample project

1. Open the Eclipse.

2. Click File -> Import.

   

3. Select General -> Existing Projects into Workspace, then click Next.

   

4. Select the sample project path via Browse, then click Finish.

   

5. See the PyDev Package Explorer.

   

Running the sample

There are two scripts separately at the service and device directories:

• service/deviceManager.py: Using Device Indentities REST APIs to create a new device identity, retrieve a device identity, and list device identities.

• device/d2cMsgSender.py: Using Send device-to-cloud message API to send device-to-cloud message from the simulated device application to IoT Hub.

You can open the Python script on Eclipse, and click the right mouse button at the script window, then click the Run As -> 2 Python Run to run the script, then see the result at the Console Window.

Code sample running result

The results for running service/deviceManager.py:

1. The result for calling the function createDeviceId(deviceId)

   • Creating an non-existed device identity, the result as below.

     (u'{"deviceId":"iotdevice3","generationId":"635937464376399955","etag":"MA==","connectionState":"Disconnected","status":"enabled","statusReason":null,"connectionStateUpdatedTime":"0001-01-01T00:00:00","statusUpdatedTime":"0001-01-01T00:00:00","lastActivityTime":"0001-01-01T00:00:00","cloudToDeviceMessageCount":0,"authentication":{"symmetricKey":{"primaryKey":"PqZ70GzRIOv8Mfap31nzDjwqsRwt8X6VTLDUM48qDGk=","secondaryKey":"gZfLMBuwgNDOuYbJZNK8ZXLGCm5WJba4CVGvXBV/0qM="}}}', 200)

   • If trying to create an existed device identity, an error information will be shown.

   (u'{"Message":"ErrorCode:DeviceAlreadyExists;A device with ID \'iotdevice1\' is already registered.\r\nTracking Id:218b497e330b41119036553381cc63de-G:GatewayWorkerRole.11-B:1-P:8a500395-cf20-45f1-831b-e0a49c9bd5fa-TimeStamp:03/16/2016 17:26:37\r\nErrorCode:DeviceAlreadyExists"}', 409)

2. The result for calling the function retrieveDeviceId(deviceId)

   (u'{"deviceId":"iotdevice1","generationId":"635928930091746067","etag":"MA==","connectionState":"Disconnected","status":"enabled","statusReason":null,"connectionStateUpdatedTime":"2016-03-16T09:46:02.5862088","statusUpdatedTime":"0001-01-01T00:00:00","lastActivityTime":"2016-03-16T09:46:02.5862088","cloudToDeviceMessageCount":0,"authentication":{"symmetricKey":{"primaryKey":"F+x9Sg9zVZC+TWnrQ1vXm0sYH/SAtvv6Wa5WhWnHdQo=","secondaryKey":"vZaSU6/8Mah4Chu28Vzx07/Feqe1a2EeDeUNEo9EY10="}}}', 200)

3. The result for calling the function listDeviceId() lists all the registered device identities.

   (u'[{"deviceId":"iotdevice1","generationId":"635928930091746067","etag":"MA==","connectionState":"Disconnected","status":"enabled","statusReason":null,"connectionStateUpdatedTime":"2016-03-16T09:46:02.5862088","statusUpdatedTime":"0001-01-01T00:00:00","lastActivityTime":"2016-03-16T09:46:02.5862088","cloudToDeviceMessageCount":0,"authentication":{"symmetricKey":{"primaryKey":"F+x9Sg9zVZC+TWnrQ1vXm0sYH/SAtvv6Wa5WhWnHdQo=","secondaryKey":"vZaSU6/8Mah4Chu28Vzx07/Feqe1a2EeDeUNEo9EY10="}}}]', 200)

The result for running device/d2cMsgSender.py includes the empty content and status code 204 from the response if message is sent successfully:

(u'', 204)