note on windowssome care is required when working with filenames that include drive letter (for example' :spam txt'in most casesfilenames are interpreted as being relative to the current working directory for exampleif the current directory is ' :\foo\'then the file ' :spam txtis interpreted as the file ' :\foo\ :spam txt'not the file ' :\spam txtsee alsofnmatch ( )glob ( )os ( signal the signal module is used to write signal handlers in python signals usually correspond to asynchronous events that are sent to program due to the expiration of timerarrival of incoming dataor some action performed by user the signal interface emulates that of unixalthough parts of the module are supported on other platforms alarm(timeif time is nonzeroa sigalrm signal is scheduled to be sent to the program in time seconds any previously scheduled alarm is canceled if time is zerono alarm is scheduled and any previously set alarm is canceled returns the number of seconds remaining before any previously scheduled alarm or zero if no alarm was scheduled (unixgetsignal(signalnumreturns the signal handler for signal signalnum the returned object is callable python object the function may also return sig_ign for an ignored signalsig_dfl for the default signal handleror none if the signal handler was not installed from the python interpreter getitimer(whichreturns the current value of an internal timer identified by which pause(goes to sleep until the next signal is received (unixset_wakeup_fd(fdsets file descriptor fd on which '\ byte will be written when signal is received thisin turncan be used to handle signals in programs that are polling file descriptors using functions such as those found in the select module the file described by fd must be opened in non-blocking mode for this to work setitimer(whichseconds [interval]sets an internal timer to generate signal after seconds seconds and repeatedly thereafter every interval seconds both of these parameters are specified as floating-point numbers the which parameter is one of itimer_realitimer_virtualor itimer_prof the choice of which determines what signal is generated after the timer has expired sigalrm is generated for itimer_realsigvtalrm is generated for lib fl ff