Create simulate.py

Author: jayascript

simpy/simulate.py

@@ -0,0 +1,103 @@
+import simpy
+import random
+
+
+class Theater(object):
+    def __init__(self, env, num_cashiers, num_servers, num_ushers):
+        self.env = env
+        self.cashier = simpy.Resource(env, num_cashiers)
+        self.server = simpy.Resource(env, num_servers)
+        self.usher = simpy.Resource(env, num_ushers)
+
+    def purchase_ticket(self, moviegoer):
+        yield self.env.timeout(random.randint(1, 2))
+
+    def sell_food(self, moviegoer):
+        yield self.env.timeout(random.randint(0, 5))
+
+    def check_ticket(self, moviegoer):
+        yield self.env.timeout(3 / 60)
+
+
+def moviegoer(env, num, theater):
+    with theater.cashier.request() as request:
+        yield request
+        yield env.process(theater.purchase_ticket(num))
+
+    with theater.server.request() as request:
+        yield request
+        yield env.process(theater.sell_food(num))
+
+    with theater.usher.request() as request:
+        yield request
+        yield env.process(theater.check_ticket(num))
+
+    departure_time = env.now
+    departure_times.append(departure_time)
+
+
+def run_theater(env, num_cashiers, num_servers, num_ushers):
+    theater = Theater(env, num_cashiers, num_servers, num_ushers)
+    interarrival = 0.20
+
+    for num in range(3):
+        env.process(moviegoer(env, num, theater))
+        arrival_time = env.now
+        arrival_times.append(arrival_time)
+
+    while True:
+        # Wait a bit before generating a new person
+        yield env.timeout(interarrival)
+
+        num += 1
+        env.process(moviegoer(env, num, theater))  # Generate the next person
+        arrival_time = env.now
+        arrival_times.append(arrival_time)
+
+
+def calculate_wait_time(arrival_times, departure_times):
+    total_wait = []
+    num_cleared = len(departure_times)
+
+    for i in range(num_cleared):
+        total_wait.append(departure_times[i] - arrival_times[i])
+
+    # Pretty print the results
+    average_wait = sum(total_wait) / num_cleared
+    minutes, frac_minutes = divmod(average_wait, 1)
+    seconds = frac_minutes * 60
+    return round(minutes), round(seconds)
+
+
+def get_user_input():
+    num_cashiers = input("Input # of cashiers working: ")
+    num_servers = input("Input # of servers working: ")
+    num_ushers = input("Input # of ushers working: ")
+    params = [num_cashiers, num_servers, num_ushers]
+    try:
+        params = [int(x) for x in params]
+    except:
+        print("Could not parse input. The simulation will use default values.")
+        params = [1, 1, 1]
+    return params
+
+
+def main():
+    # Setup
+    random.seed(42)
+    num_cashiers, num_servers, num_ushers = get_user_input()
+
+    # Run the simulation
+    env = simpy.Environment()
+    env.process(run_theater(env, num_cashiers, num_servers, num_ushers))
+    env.run(until=90)
+
+    # View the results
+    mins, secs = calculate_wait_time(arrival_times, departure_times)
+    print(f"The average wait time is {mins} minutes and {secs} seconds.")
+
+
+if __name__ == "__main__":
+    arrival_times = []
+    departure_times = []
+    main()