202 response means that it is Accepted.
Even though it is a response for success, it tells you that the action which you requested has been started but yet to be completed.
To stop this asynchronous call where your InvocationType parameter is set to Event, you have to change it to RequestResponse. And after you do that, you can get the returned data like this:
data = invoke_response['Payload'].read() //This will return bytes
If you want it in string or JSON, try this:
data = invoke_response['Payload'].read().decode()