Mix of decorators and module level function to compose multiple capabilities (Python)

carbonsession.py

import carbon

video_stream = ...

# Module level function lets you pick a stream, "features" and go 
# (this assumes there is a default configuration for each feature/category/model)
for event in carbon.recognize(video_stream, features=['faceDetection', 'vehicleDetection']):
    print(event)

# Slightly more involved scenario with custom configurations and a dedicated session...
# The top level recognize would also take specific configuration in addition to names of features
face_detection_configuration = carbon.FaceDetection(configuration_property1 = ...)
vehicle_detection_configuration = carbon.VehicleDetection(some_other_configuration_property = ...)

session = carbon.Session(features=[face_detection_configuration, vehicle_detection_configuration])

@session.on_event('faceDetected') 
def handle_face_detected(event):
    print(event)

@session.on_event('vehicleDetected') 
def handle_on_vehicle_detected(event):
    print(event)

    # Now, I can also reach in to the session (since it is - if you use the "normal" flow bound here)
    # Alternatively we can have a session parameter or a session.current that one can use...
    # This is riffing on the "start/stop/add new features as you go along scenario"
    session.stop_feature('faceDetection') # No longer interested in faces
    session.start_feature('dogDetection') # But I do like dogs...

# Now, if you don't like the recognizer pattern, you can also bind event handlers directly
# This is equivalent to what the decorator does "under the hood"
session.add_handler('puppyDetection', lambda event: print('Yay, puppy!'))

session.recognize(video_stream)