python - 类型错误 : must be string, 不是 strptime 的日期

Question

我正在尝试实现以下内容:给定这样一个 Date 对象数组，返回第三个最新日期的函数

这是我想出的解决方案，但出现以下错误:

TypeError: must be string, not date 

<小时/>

import datetime
def third_latest():
    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']
    dates = [datetime.datetime.strptime(ts, "%Y-%m-%d") for ts in timestamps]
    dates.sort()
    sorteddates = [datetime.datetime.strftime(ts, "%Y-%m-%d") for ts in dates]
    return str(sorteddates[3])

def main():
    third_latest()

if __name__ == "__main__":
    main()

Answer 1

strftime根据格式将datetime对象转换为字符串。

替换:

sorteddates = [datetime.datetime.strftime(ts, "%Y-%m-%d") for ts in dates]

与

sorteddates = [ts.strftime("%Y-%m-%d") for ts in dates]

查看 documentation对于strftime。

此外，您还可以查看 working version of your code here .