replace exit() and quit() with sys.exit()

tilde-train.py

@@ -129,7 +129,7 @@ def test_user_car():
   except:
     print("ERROR: Couldn't open " + fname)
     print("Either it doesn't exist, or is not readble by the tilde.train script.")
-    exit()
+    sys.exit(1)
 
   choochoo_string = myfile.read()
   choochoo_list = choochoo_string.split("\n")
@@ -166,7 +166,7 @@ def test_user_car():
     print(string.printable.strip())
     print("")
     print("Yours contained " + bad_chars)
-    exit()
+    sys.exit(1)
 
 #  print("")
 #  print("Test results:")
@@ -178,17 +178,17 @@ def test_user_car():
     print("FAIL. Your train car is too tall.")
     print("It should be no taller than " + str(max_y) + " lines in height.")
     myfile.close()
-    exit()
+    sys.exit(1)
 
   if train_length > max_x:
     print("FAIL. Your train car is too long.")
     print("It should be no longer than " + str(max_x) + " characters in length.")
     myfile.close()
-    exit()
+    sys.exit(1)
 
   print("PASS. Your train car will work on the tilde.town tracks! :)")
   myfile.close()
-  exit()
+  sys.exit()
 
 def link_car(car):
   for idx,row in enumerate(car):
@@ -302,24 +302,24 @@ def chuggachugga(stdscr):
 def handler(signal_received, frame):
   print("Oops. The train broke.  The engineer is looking into it!")
   print("(Note: the train does not work in all terminals yet.)")
-  exit(0)
+  sys.exit(1)
 
 default_car = validate_car(default_car)
 
 if len(sys.argv) == 2 and ("-h" in sys.argv[1] or "help" in sys.argv[1]):
   print_help()
-  quit()
+  sys.exit()
 
 if len(sys.argv) == 2 and ("-t" in sys.argv[1] or "test" in sys.argv[1]):
   test_user_car()
-  quit()
+  sys.exit()
 
 if len(sys.argv) == 2 and ("-p" in sys.argv[1] or "print" in sys.argv[1]):
   print_train = True
 
 if len(sys.argv) == 2 and ("-a" in sys.argv[1] or "all" in sys.argv[1]):
   print_all_cars()
-  quit()
+  sys.exit()
 
 
 ## start a loop that collects all .choochoo files and processes on in each loop
@@ -368,7 +368,7 @@ if print_train:
   print("<pre>")
   print(train_str)
   print("</pre>")
-  quit()
+  sys.exit()
 
 pad_str = " "*train_len
 train.insert(0,pad_str)