events.request_success += test_success_handle TypeError: unsupported operand type(s) for +=: 'EventHook' and 'function' - locust

Question

I am new to locust tool and trying to write the individual success and failure to console. Here is the error received during execution.
Error:
events.request_success += test_success_handle
TypeError: unsupported operand type(s) for +=: 'EventHook' and 'function'
Code:
from locust import events
hostname = socket.gethostname()
def test_success_handle(request_type, name, response_time, response_length, **kwargs):
SUCCESS_TEMPLATE = '[{"measurement": "%s","tags": {"hostname":"%s","requestName": "%s","requestType": "%s","status":"%s"' \
'},"time":"%s","fields": {"responseTime": "%s","responseLength":"%s"}' \
'}]'
json_string = SUCCESS_TEMPLATE % (
"ResponseTable", hostname, name, request_type, "success", datetime.datetime.now(tz=pytz.UTC), response_time,
response_length)
print(json_string)
def test_fail_handle(request_type, name, response_time, response_length, exception, **kwargs):
FAIL_TEMPLATE = '[{"measurement": "%s","tags": {"hostname":"%s","requestName": "%s","requestType": "%s","exception":"%s","status":"%s"' \
'},"time":"%s","fields": {"responseTime": "%s","responseLength":"%s"}' \
'}]'
json_string = FAIL_TEMPLATE % (
"ResponseTable", hostname, name, request_type, exception, "fail", datetime.datetime.now(tz=pytz.UTC),
response_time, response_length)
print(json_string)
events.request_success += test_success_handle()
events.request_failure += test_fail_handle()
Could you please help me.. Is there a another way to resolve the issue with latest version of locust. Thank you
In the code we added POST request and and trying to fire the event and send it to handler to display in the console.

Answer 1

Try to use event annotations, the latest stable version of locust implements a method for what you need to do: add_listener, see https://docs.locust.io/en/stable/api.html
from locust import events, HttpLocust
hostname = socket.gethostname()
#events.request_success.add_listener
def test_success_handle(request_type, name, response_time, response_length, **kwargs):
SUCCESS_TEMPLATE = '[{"measurement": "%s","tags": {"hostname":"%s","requestName": "%s","requestType": "%s","status":"%s"' \
'},"time":"%s","fields": {"responseTime": "%s","responseLength":"%s"}' \
'}]'
json_string = SUCCESS_TEMPLATE % (
"ResponseTable", hostname, name, request_type, "success", datetime.datetime.now(tz=pytz.UTC), response_time,
response_length)
print(json_string)
#events.request_failure.add_listener
def test_fail_handle(request_type, name, response_time, response_length, exception, **kwargs):
FAIL_TEMPLATE = '[{"measurement": "%s","tags": {"hostname":"%s","requestName": "%s","requestType": "%s","exception":"%s","status":"%s"' \
'},"time":"%s","fields": {"responseTime": "%s","responseLength":"%s"}' \
'}]'
json_string = FAIL_TEMPLATE % (
"ResponseTable", hostname, name, request_type, exception, "fail", datetime.datetime.now(tz=pytz.UTC),
response_time, response_length)
print(json_string)
class MyLocust(HttpLocust):
events.request_success.add_listener(individual_success_handle)
events.request_failure.add_listener(individual_fail_handle)

Answer 2

I think you need to lose the parentheses, and keep the methods outside the Locust class like this
from locust import events, HttpLocust
hostname = socket.gethostname()
def test_success_handle(request_type, name, response_time, response_length, **kwargs):
SUCCESS_TEMPLATE = '[{"measurement": "%s","tags": {"hostname":"%s","requestName": "%s","requestType": "%s","status":"%s"' \
'},"time":"%s","fields": {"responseTime": "%s","responseLength":"%s"}' \
'}]'
json_string = SUCCESS_TEMPLATE % (
"ResponseTable", hostname, name, request_type, "success", datetime.datetime.now(tz=pytz.UTC), response_time,
response_length)
print(json_string)
def test_fail_handle(request_type, name, response_time, response_length, exception, **kwargs):
FAIL_TEMPLATE = '[{"measurement": "%s","tags": {"hostname":"%s","requestName": "%s","requestType": "%s","exception":"%s","status":"%s"' \
'},"time":"%s","fields": {"responseTime": "%s","responseLength":"%s"}' \
'}]'
json_string = FAIL_TEMPLATE % (
"ResponseTable", hostname, name, request_type, exception, "fail", datetime.datetime.now(tz=pytz.UTC),
response_time, response_length)
print(json_string)
class MyLocust(HttpLocust):
events.request_success += test_success_handle
events.request_failure += test_fail_handle

Answer 3

In case someone is still looking at solution for this type of error:
With Locust 1.0+ version (I'm currently at 1.4.1) there is a new way of adding eventHooks.
Instead of:
events.request_success += test_success_handle
events.request_failure += test_fail_handle
Do this:
events.request_success.add_listener(test_success_handle)
events.request_failure.add_listener(test_fail_handle)
And make sure it is defined inside def __init__

Answer 4

Can you try the below code to register your callback functions:
# registering the hooks for success & error events in Locust lifecycle
locust.events.request_success += test_success_handle
locust.events.request_failure += test_fail_handle