如何在Python中定义日期时间对象？

Question

time1 = datetime.now();time1 -= time1;time2 = datetime.now();time2 -= time2;多数民众赞成在我试图定义一个日期时间等于零。正确的做法是什么？那就是我想做的事：import urllib2from datetime import datetimetime1 = datetime.now();time1 -= time1;time2 = datetime.now();time2 -= time2;for i in range(0, 5):    x = datetime.now()    response = urllib2.urlopen("http://www.google.com")    time1 += datetime.now() - x    x = datetime.now()    response = urllib2.urlopen("http://facebook.com")     time2 += datetime.now() - xprint time1print time2它有效，但是我认为这样做是错误的方式。