按月份将嵌套列表中的日期字符串拆分到组列表- Python

import datetime

def parse_date(date_str):
    return datetime.datetime.strptime(date_str, "%Y-%m-%d")

def split_dates_by_month(date_list):
    groups = {}
    for date_str in date_list:
        date = parse_date(date_str)
        month = date.strftime("%Y-%m")
        if month not in groups:
            groups[month] = []
        groups[month].append(date_str)
    return list(groups.values())

date_list = [['2022-01-01', '2022-01-02', '2022-01-03'], ['2022-02-01', '2022-02-02', '2022-02-03']]
result = split_dates_by_month([date for sublist in date_list for date in sublist])
print(result)

[['2022-01-01', '2022-01-02', '2022-01-03'], ['2022-02-01', '2022-02-02', '2022-02-03']]