python根据输入的字符串日期返回对应的财务季度报告日期

 1 import xlrd
 2 import xlwt
 3 from datetime import datetime
 4 #输入的s为str形式，如\'2017-12-18\'
 5 def to_date(s):
 6     d=datetime.strptime(s,"%Y-%m-%d")
 7     return(d)
 8 def to_quarter(riqi):
 9     yr=to_date(riqi).year
10     qrt=[[datetime(yr, 3, 31),0],
11         [datetime(yr, 6, 30),0],
12         [datetime(yr, 9, 30),0],
13         [datetime(yr, 12, 31),0]]
14     for t in qrt:
15         if to_date(riqi) <= t[0]:
16             return(t[0])