operating system services parameter description "sc_tzname_maxmaximum number of bytes in time zone name "sc_open_maxmaximum number of files process can open at one time "sc_job_controlsystem supports job control "sc_saved_idsindicates whether each process has saved set-user-id and saved set-group-id urandom(nreturns string containing random bytes generated by the system (for example/dev/urandom on unixthe returned bytes are suitable for cryptography exceptions the os module defines single exception to indicate errors error exception raised when function returns system-related error this is the same as the built-in exception oserror the exception carries two valueserrno and strerr the first contains the integer error value as described for the errno module the latter contains string error message for exceptions involving the file systemthe exception also contains third attributefilenamewhich is the filename passed to the function os path the os path module is used to manipulate pathnames in portable manner it' imported by the os module abspath(pathreturns an absolute version of the path name pathtaking the current working directory into account for exampleabspath(/python/foo'might return '/home/beazley/python/foobasename(pathreturns the base name of path name path for examplebasename('/usr/localpython'returns 'pythoncommonprefix(listreturns the longest string that' prefix of all strings in list if list is emptythe empty string is returned dirname(pathreturns the directory name of path name path for exampledirname('/usr/localpython'returns '/usr/localexists(pathreturns true if path refers to an existing path returns false if path refers to broken symbolic link lib fl ff