如何使用Python SDK将变量发送到Azure事件中心

Question

如果我有一个包含温度值的变量，如何使用ServiceBusService.send_event发送它？

Answer 1

It depends on how you are consuming it on the other side of event hubs. If you are using Azure Stream Analytics you must make sure that the format you are sending to event hubs is either json, csv, or arvo .

If you have a variable, it would be simple enough to create a dictionary, serialize it using Python's json library and send the resulting string. Example:

from azure.servicebus.control_client import ServiceBusService
import json;

sbs = ServiceBusService("your_namespace",
                        shared_access_key_name="your_policy_name",
                        shared_access_key_value="your_policy_secret")

# build dictionary and send value
temp = {'DeviceId': 'dev-01', 'Temperature': str(i)}
sbs.send_event('woodstove2', json.dumps(temp))

Answer 2

Please make sure you have created a ServiceBus namespace for EventHub. If not, please refer to "Create an Event Hub" section of the article https://azure.microsoft.com/en-us/documentation/articles/event-hubs-csharp-ephcs-getstarted/ .

You will get ServiceBus SAS name & key in the Service Bus Configure page as below.

If the service bus does not contain an event hubs, you can create it manually via clicking the tab "event hubs", or create it by using Python SDK.

from azure.servicebus import ServiceBusService

servns = '<service_bus _namespace>'
key_name = '<service_bus_sas_keyname>'  # SharedAccessKeyName from Azure portal
key_value = '<service_bus_sas_key>'  # SharedAccessKey from Azure portal
sbs = ServiceBusService(service_namespace=servns,
                        shared_access_key_name=key_name,
                        shared_access_key_value=key_value) # Create a ServiceBus Service Object
flag = sbs.create_event_hub('<event_hub_name>') # Create a Event Hub for the ServiceBus. If it exists then return true, else return false
print(flag)
event_data = '<event_data>'
sbs.send_event('<event_hub_name>', event_data) # Send event data to your Event Hub, like real-time temperature data

According to your scene, you can serialize event data to JSON string, CSV String with header as jsturtevant said.

For temperature example:

1. JSON

event_data = '{"deviceId": "dev01", "time": "2015-08-24 12:34:45", "temperature": 30.0 }'

2. CSV

event_data = 'deviceId,time,temperature\\ndev01,2015-08-24 12:34:45,30.0'

For more information about ServiceBus Python SDK, you can refer to the part - "Usage" of the link "README.rst" https://github.com/Azure/azure-sdk-for-python/tree/master/azure-servicebus .