How do I capture SIGINT in Python?

Register your handler with signal.signal like this:

#!/usr/bin/env pythonimport signalimport sysdef signal_handler(sig, frame):    print('You pressed Ctrl+C!')    sys.exit(0)signal.signal(signal.SIGINT, signal_handler)print('Press Ctrl+C')signal.pause()

Code adapted from here.

More documentation on signal can be found here. 

You can treat it like an exception (KeyboardInterrupt), like any other. Make a new file and run it from your shell with the following contents to see what I mean:

import time, sysx = 1while True:    try:        print x        time.sleep(.3)        x += 1    except KeyboardInterrupt:        print "Bye"        sys.exit()

And as a context manager:

import signalclass GracefulInterruptHandler(object):    def __init__(self, sig=signal.SIGINT):        self.sig = sig    def __enter__(self):        self.interrupted = False        self.released = False        self.original_handler = signal.getsignal(self.sig)        def handler(signum, frame):            self.release()            self.interrupted = True        signal.signal(self.sig, handler)        return self    def __exit__(self, type, value, tb):        self.release()    def release(self):        if self.released:            return False        signal.signal(self.sig, self.original_handler)        self.released = True        return True

To use:

with GracefulInterruptHandler() as h:    for i in xrange(1000):        print "..."        time.sleep(1)        if h.interrupted:            print "interrupted!"            time.sleep(2)            break

Nested handlers:

with GracefulInterruptHandler() as h1:    while True:        print "(1)..."        time.sleep(1)        with GracefulInterruptHandler() as h2:            while True:                print "\t(2)..."                time.sleep(1)                if h2.interrupted:                    print "\t(2) interrupted!"                    time.sleep(2)                    break        if h1.interrupted:            print "(1) interrupted!"            time.sleep(2)            break

From here: https://gist.github.com/2907502