State Machine Framework

An experiement with state machine modeling

install

pip3 install -e .

run test

python3 -m unittest tests.test_machine

Usage

• States and Events can be any object.
• If state is a callable object, then it will be triggered to call side effects.
• You use states as nodes and events as edges.

Use the add(from_state: object, event: object, to_state: object) method of Machine class to model the state machine.

from machine.machine import Machine

m = Machine("Start")

m.add("Start", "red", "R1") \
 .add("Start", "yellow", "Y1") \
 .add("R1", "red", "R2") \
 .add("R1", "yellow", "Y1") \
 .add("R2", "red", "R3") \
 .add("R2", "yellow", "Y1") \
 .add("R3", "red", "R4") \
 .add("R3", "yellow", "Y1") \
 .add("R4", "red", "R4") \
 .add("R4", "yellow", "Y1") \
 .add("Y1", "red", "R1") \
 .add("Y1", "yellow", "Y2") \
 .add("Y2", "red", "R1") \
 .add("Y2", "yellow", "Y3") \
 .add("Y3", "red", "R1") \
 .add("Y3", "yellow", "Y4") \
 .add("Y4", "red", "R1") \
 .add("Y4", "yellow", "Y4")

Then, you can iterate a list of events with

for state in m.iterate_input(['red', 'yellow', 'red', 'yellow', 'red', 'yellow', 'red', 'yellow']):
    print(state)

# prints: R1, Y1, R1, Y1, R1, Y1, R1, Y1