python时间戳数字转为字符串格式表达

import datetime

def getdate(date):
    s_date = datetime.date(1899, 12, 31).toordinal() - 1
    if isinstance(date, float):
        date = int(date)
    d = datetime.date.fromordinal(s_date + date)
    return d.strftime("%Y-%m-%d")

print getdate(41400.0)

输出：2013-05-06