1. 获取本周周一日期
   用timedelta函数做一个小算法：

from datetime import datetime, timedelta
 
 
def this_monday(today):
    """
    :function: 获取本周周一日期
    :param today:
    :return: 返回周一的日期
    :return_type: string
    """
    today = datetime.strptime(str(today), "%Y%m%d")
    return datetime.strftime(today - timedelta(today.weekday()), "%Y%m%d")

2. 获取本周周日日期
   算法同上

from datetime import datetime, timedelta
 
 
def this_sunday(today):
    """
    :function: 获取本周周日日期
    :param today:
    :return: 返回周日日期
    :return_type: string
    """
    today = datetime.strptime(str(today), "%Y%m%d")
    return datetime.strftime(today + timedelta(7 - today.weekday() - 1), "%Y%m%d")