“'Mr Bassington-Bassington has just telephoned, sir.'” Python has two signal handlers Blocking a signal is different than ignoring it Python doesn't pass SA_RESTART Safe signal idioms Python signal handlers are unexpectedly reentrant Is it safe to call print in a Python signal handler? time.sleep and signal interrupts Python siginterrupt is confusing We learned earlier that because Python has two signal handlers , the onerous restrictions on what functions a signal handler may call do not apply to Python, because CPython does not call the user-supplied Python signal handler inside the low-level C signal handler, where those restrictions do apply, but arranges for it to be called later, when the interpreter is in a consistent state. We also learned that Python signal handlers are unexpectedly reentrant – if a signal arrives while a Python signal handler is running, the signal handler can be called again in the middle of the first call.…