SIGINT *is* keyboard interrupt.  Since less at least seems to ignore SIGQUIT I suppose also ignoring that would be reasonable, since the user (should) by analogy expect that behavior while the pager is active.  Note, however, that the signals we are ignoring are in the parent process, not the child as is the case for system.  So one can argue that letting the python process die when SIGQUIT is received would also be reasonable, and arguably is the less surprising option.