Handle a user wanting to quit a looping terminal program.

handle_ctrl_c_example.py

import signal
import sys
import time
def signal_handler(signal, frame):
    print("Wasting your time...")
    time.sleep(3)
    print("Goodbye")
    raise SystemExit
signal.signal(signal.SIGINT, signal_handler)

print("hello!, this program will check if a year is a leap year")
while True:
    while True:
        global year
        year = input("year: ")
        if year.lower() == "q":
            signal.raise_signal( signal.SIGINT )
        try:
            year = int(year)
            break
        except:
            print("Only decimals or the letter q (to quit) are accepted")

    #math
    leap = (
        (year % 4 == 0) and
        (
            (year % 100 != 0) or
            (year % 400 == 0)
        )
    )
    #checks
    if leap:
         print("year: "+str(year)+" is a leapyear")
    else:
         print("year: "+str(year)+" is not a leaapyear")