automat_finite_state_machine_coffee_machine_heating_brewing.py

1from __future__ import print_function
2from automat import MethodicalMachine
3
4class CoffeeMachine(object):
5    _machine = MethodicalMachine()
6
7    @_machine.input()
8    def heat_up(self):
9        "The user pressed the 'heat up' button."
10
11    @_machine.input()
12    def brew(self):
13        "The user pressed the 'brew' button."
14
15    @_machine.output()
16    def _begin_heating(self):
17        print("Heating up...")
18
19    @_machine.output()
20    def _brew_coffee(self):
21        print("Brewing coffee!")
22
23    @_machine.state(initial=True)
24    def idle(self):
25        "The machine is currently idle."
26
27    @_machine.state()
28    def heating(self):
29        "The machine is heating up."
30
31    # Define the transitions
32    idle.upon(heat_up, enter=heating, outputs=[_begin_heating])
33    heating.upon(brew, enter=idle, outputs=[_brew_coffee])
34
35# Usage example:
36coffee_machine = CoffeeMachine()
37coffee_machine.heat_up()
38coffee_machine.brew()