def _newer(a, b):
 if (not os.path.exists(a)):
  return False
 if (not os.path.exists(b)):
  return True
 return (os.path.getmtime(a) >= os.path.getmtime(b))

def _newer ( a , b ) : if ( not os . path . exists ( a ) ) : return False if ( not os . path . exists ( b ) ) : return True return ( os . path . getmtime ( a ) >= os . path . getmtime ( b ) )
inquire whether file a was written since file b .