python 2.4中datetime有strftime方法，而无strptime方法。不能对字符串进行格式转换。比如不能将“2013-10-22”转化为日期。

2.4中字符串转日期并相减？怎么做？

必须google，不能百度：

import time

format =
'%Y-%m-%d %H:%M:%S'

print time.mktime(time.strptime(time2,
format)) - time.mktime(time.strptime(time1,
format))

For Python 2.5+，just  use datetime

from datetime import datetime
format = '%Y-%m-%d %H:%M:%S'

print datetime.strptime(time2, format) -

        datetime.strptime(time1, format)

# 1 day, 0:00:00

#time1 and time 2 are string as date, like "2013-10-22"

此外2.4中还可以：

from time import strptime

from
datetime import datetime

str_to_datetime =
lambda st: datetime(*strptime(st,
'%Y-%m-%d %H:%M:%S')[:6])

str_to_datetime('2010-04-20 10:07:30')

或者

import time

time1 =
"2010-04-20 10:07:30"

time_tuple = time.strptime(time1,
"%Y-%m-%d %H:%M:%S")

timestamp = time.mktime(time_tuple)

而实际上还可以用

datetime(*(time.strptime(date_string, format)[0:6]))

拆开：

t = time.strptime(timepoint, '%Y-%m-%d')

resulttime = datetime.datetime(*t[:6])