如何用python编写比较器函数对日期进行排序
我想写一个comparator函数来对下面的日期列表进行排序如何用python编写比较器函数对日期进行排序,python,Python,我想写一个comparator函数来对下面的日期列表进行排序 timestamps = ['2011-06-2', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30', '2010-11-26', '2010-11-23', '2010-11-22', '2010-11-16'] 怎么做 更新: 我有:ti
timestamps = ['2011-06-2', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30', '2010-11-26', '2010-11-23', '2010-11-22', '2010-11-16']
怎么做
更新:
我有:timestamps.sort(key=lambda x:time.mktime(time.strtime(x,“%Y-%m-%d”))
但是我想写一个比较器函数。这可能不是实现它的方法,即使它产生了正确的结果
timestamps.sort(key=lambda d:"%d%02d%02d"%tuple(map(int,d.split('-'))))
以下是其中一种方法:
from datetime import datetime
timestamps = ['2011-06-2', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30', '2010-11-26', '2010-11-23', '2010-11-22', '2010-11-16']
converted_timestamps = [datetime.strptime(x, '%Y-%m-%d') for x in timestamps]
sorted_timestamps = sorted(converted_timestamps)
sorted_timestamps_as_string = [datetime.strftime(date, "%Y-%m-%d") for date in sorted_timestamps]
print(sorted_timestamps_as_string)
输出:
$python tes.py
['2010-01-12'、'2010-01-14'、'2010-02-07',
'2010-02-11', '2010-11-16', '2010-11-22', '2010-11-23', '2010-11-26',
'2010-12-02', '2010-12-13', '2011-02-04', '2011-06-02', '2011-08-05',
‘2011-11-30’
我觉得它更具可读性。一种简单的方法。转换为
datetime
对象,排序,然后转换回字符串
from datetime import datetime
def sort_dates(string_dates):
dates = [datetime.strptime(string_date, "%Y-%m-%d") for string_date in string_dates]
dates.sort()
return [datetime.strftime(date, "%Y-%m-%d") for date in dates]
样本输出:
>>> print sort_dates(['2011-06-2', '2011-08-05', '2011-02-04', '2010-1-14', '2010-12-13', '2010-1-12', '2010-2-11', '2010-2-07', '2010-12-02', '2011-11-30', '2010-11-26', '2010-11-23', '2010-11-22', '2010-11-16'])
['2010-01-12', '2010-01-14', '2010-02-07', '2010-02-11', '2010-11-16', '2010-11-22', '2010-11-23', '2010-11-26', '2010-12-02', '2010-12-13', '2011-02-04', '2011-06-02', '2011-08-05', '2011-11-30']
这些是字符串,不是日期。先把它们转换成日期,然后按常规方式排序。你自己做过任何努力吗?如果是这样,如果您与他人分享,可能会有人提供帮助。Python不赞成使用
cmp
参数进行sort
,而赞成使用key
。为什么要编写比较器函数?@dan04,因为我不想使用任何内置模块。