Python 以小时为单位获取Datetime之间的差异，将两个四舍五入设置为2

通过四舍五入到小数点后2位，获得两个datetime之间以小时为单位的差值

> `Started                     Ended`                     Hours
   2020-10-01 09:29:20         2020-10-01 17:43:28         8.2
   2020-10-31 09:26:43         2020-10-31 18:57:40         9.5
   2020-10-31 09:18:57         2020-10-31 21:06:30         11.8

与and一起使用，最后除以and使用：

另一个例子：

from datetime import datetime
beg = '08:00:10'
end = '17:16:24' 

print('end = ',end, 'type: ',type(end))

dur = datetime.strptime(end, '%H:%M:%S') - datetime.strptime(beg, '%H:%M:%S')

result = dur.total_seconds()/3600

result = round(result, 2)

print(result)

from datetime import datetime
beg = '08:00:10'
end = '17:16:24' 

print('end = ',end, 'type: ',type(end))

dur = datetime.strptime(end, '%H:%M:%S') - datetime.strptime(beg, '%H:%M:%S')

result = dur.total_seconds()/3600

result = round(result, 2)

print(result)