以下是一个示例代码，演示了如何按照邮件行分割后的星期进行排序：

import re

# 定义邮件行的样式
email_line_pattern = r"\w+\s+(\d+)\s+(\w+)"
# 定义星期的顺序
week_order = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]

# 示例邮件行列表
email_lines = [
    "From: Mon 25 Jan",
    "From: Sun 31 Jan",
    "From: Tue 26 Jan",
    "From: Thu 28 Jan",
    "From: Sat 30 Jan",
]

# 提取邮件行中的日期和星期
dates_and_weeks = []
for line in email_lines:
    match = re.search(email_line_pattern, line)
    if match:
        date = match.group(1)
        week = match.group(2)
        dates_and_weeks.append((date, week))

# 按照星期的顺序进行排序
dates_and_weeks.sort(key=lambda x: week_order.index(x[1]))

# 打印排序结果
for date, week in dates_and_weeks:
    print(f"Date: {date}, Week: {week}")

运行上述代码，输出结果将按照邮件行分割后的星期进行排序。