fix a code to terminate process

main.py

@@ -6,15 +6,19 @@ import time
 import bitbank
 
 
+alive = True
+
 def main():
+  global alive
   procs = [*bitbank.init()]
-  while True:
+  while alive:
     for i in range(len(procs)):
       procs[i].tick()
     time.sleep(1)
 
 def on_exit(sig, x):
-  print(f"received {sig}")
+  global alive
+  alive = False
 
 proc = multiprocessing.Process(target = main)
 proc.start()