class SimulationEngine():
"""
Class responsible for running the simulation by working with the Building,
Passengers, and Elevator classes
Attributes:
num_floors: number of floors in the building indexed from 0 to num_floors-1
passenger_list: list of passengers
elevator: elevator class used in the building
building: building class
"""
END_MESSAGE = "All passengers have been served - End of simulation"
TIME_MESSAGE = "Average journey time: %s"
MOVE_MESSAGE = "Elevator moved from floor %s to floor %s"
PICKUP_MESSAGE = "Elevator picks up passenger %s at floor %s"
DROPOFF_MESSAGE = "Elevator drops off passenger %s at floor %s"
COLUMN_NAMES = ["Elevator", "|", "Floor", "# people"]
FLOOR_FORMAT = "{:>10}" * len(COLUMN_NAMES)
ELEVATOR_ON_FLOOR = "X"
NO_ELEVATOR = " "
DELIMITER = "|"
TIME_PER_FLOOR = 1.5
STOP_TIME = 6
def __init__(self,
num_floors,
total_passengers,
elevator_type,
capacity,
should_plot=True):
self.num_floors = num_floors
self.total_passengers = total_passengers
self.elevator_type = elevator_type
self.elevator_capacity = capacity
self.should_plot = should_plot
# Initialize passengers, elevator, and Building
self.reset()
def reset(self):
"""
Initializes/resets the simulation to its initial state
"""
# Generate a list of passengers based on total number of passengers
self.passenger_list = [
Passenger(i, self.num_floors)
for i in range(1, self.total_passengers + 1)
]
self.elevator = ElevatorFactory.get_elevator(self.num_floors,
self.elevator_type,
self.passenger_list,
self.elevator_capacity)
self.building = Building(self.num_floors, self.passenger_list)
def run(self):
"""
Main method for simulation. The while True loop continues until
all requests are fulfilled
"""
self._print_state([], 0, True)
total_wait_time = 0
distance_moved = 0
while True:
# Used to print current state
passenger_movements = []
# Pick-up/drop-off passengers on current floor
for passenger in self.elevator.requests:
if passenger.at_destination:
continue
# Add time waited to total
total_wait_time += distance_moved * self.TIME_PER_FLOOR + self.STOP_TIME
# Try pick-up
pickup_move = self._pickup_passenger(passenger)
# If passenger entered the elevator, store movement
if pickup_move is not None:
passenger_movements.append(pickup_move)
# Try drop-off
dropoff_move = self._dropoff_passenger(passenger)
# If passenger left the elevator, store movement
if dropoff_move is not None:
passenger_movements.append(dropoff_move)
# If there is no request left, we end the simulation and break the loop.
if self.elevator.all_requests_completed():
average_journey = 0
if self.total_passengers != 0:
average_journey = total_wait_time / self.total_passengers
if self.should_plot:
print(self.END_MESSAGE)
print(self.TIME_MESSAGE % (average_journey))
return average_journey
distance_moved = self.elevator.move()
self._print_state(passenger_movements, distance_moved)
def _pickup_passenger(self, passenger):
"""
Pick-up passenger given that elevator is on the floor
and the maximum capacity is not reached
"""
if passenger.current == self.elevator.curr_floor \
and passenger.in_elevator == False \
and self.elevator.num_passengers < self.elevator.capacity:
passenger.in_elevator = True
self.elevator.num_passengers += 1
return (self.PICKUP_MESSAGE %
(passenger.id, self.elevator.curr_floor))
return None
def _dropoff_passenger(self, passenger):
"""
Drop-off passenger given that the destination is reached
"""
if passenger.destination == self.elevator.curr_floor \
and passenger.in_elevator == True:
self.elevator.num_passengers -= 1
passenger.at_destination = True
return (self.DROPOFF_MESSAGE %
(passenger.id, self.elevator.curr_floor))
return None
def _print_state(self, passenger_movements, distance_moved, initial=False):
"""
Prints the current state of the simulation
"""
if not self.should_plot:
return
# Clear output
os.system('clear')
# clear_output(wait=True)
# Illustration of current state
print(self.FLOOR_FORMAT.format(*self.COLUMN_NAMES))
for floor in range(self.num_floors - 1, -1, -1):
floor_elements = []
if floor == self.elevator.curr_floor:
floor_elements.append(self.ELEVATOR_ON_FLOOR)
else:
floor_elements.append(self.NO_ELEVATOR)
floor_elements.append(self.DELIMITER)
floor_elements.append(floor)
floor_elements.append(
str(self.building.get_passengers_on_floor(floor)))
print(self.FLOOR_FORMAT.format(*floor_elements))
if initial:
time.sleep(1)
return
print("=" * 50)
print("Number of people in elevator while moving: %s" %
self.elevator.num_passengers)
print("Number of passengers who have received service: %s out of %s" %
(self.elevator.requests_served(), len(self.elevator.requests)))
# Display next elevator movement
if self.elevator.is_moving_up():
print(self.MOVE_MESSAGE %
(self.elevator.curr_floor - distance_moved,
self.elevator.curr_floor))
elif not self.elevator.is_moving_up():
print(self.MOVE_MESSAGE %
(self.elevator.curr_floor + distance_moved,
self.elevator.curr_floor))
# Display passenger movements
print("=" * 50)
for movement in passenger_movements:
print(movement)
time.sleep(1)
