python如何统计代码运行的时长

#!/usr/bin/env python import datetimeimport time start_time = datetime.datetime.now()time.sleep(5)end_time = datetime.datetime.now()delta = end_time - start_timedelta_gmtime = time.gmtime(delta.total_seconds())duration_str = time.strftime("%H:%M:%S", delta_gmtime) print "start time:", start_timeprint "end time:", end_timeprint "delta_gmtime:", delta_gmtimeprint "duration:", duration_str

flying-bird@flyingbird:~/examples/python/time_test$ ./time_test.py start time: 2015-06-09 20:11:47.437286end time: 2015-06-09 20:11:52.440018delta_gmtime: time.struct_time(tm_year=1970, tm_mon=1, tm_mday=1, tm_hour=0, tm_min=0, tm_sec=5, tm_wday=3, tm_yday=1, tm_isdst=0)duration: 00:00:05flying-bird@flyingbird:~/examples/python/time_test$ 

import datetimeimport time class TimeDuration(object):  'Time duration.'    def __init__(self):    pass      def start(self):    self.start_time = datetime.datetime.now()    self.end_time = None      def stop(self):    if self.start_time is None:      print "ERROR: start() must be called before stop()."      return          self.end_time = datetime.datetime.now()      def getDurationStr(self):    'String of duration with the format "%H:%M:%S".'    if self.start_time is None or self.end_time is None:      print "ERROR: start() and stop() must be called first.";      return        delta = self.end_time - self.start_time    delta_gmtime = time.gmtime(delta.total_seconds())    return time.strftime("%H:%M:%S", delta_gmtime)

flying-bird@flyingbird:~/examples/python/time_test$ cat time_test2.py#!/usr/bin/env python import timeimport time_utils duration = time_utils.TimeDuration()duration.start()time.sleep(5)duration.stop() print duration.getDurationStr() flying-bird@flyingbird:~/examples/python/time_test$ ./time_test2.py00:00:05flying-bird@flyingbird:~/examples/python/time_test$