python - 如何从两个间隔中获取分割月份？

Question

我有两个 YYYYmm 格式的日期

start : 202307
end : 202612

想要根据提供的间隔按间隔分割它们

例如 split_months ('202307,'202405',5)，会给我

((202307,202311), (202312,202404), (202405,202405))

尝试使用以下代码，机器人陷入逻辑

def split_months(start, end, intv):
    from datetime import datetime
    periodList = []
    periodRangeSplitList = []

    start = datetime.strptime(start ,"%Y%m")
    end = datetime.strptime(end ,"%Y%m")
    mthDiff = relativedelta.relativedelta(end, start)

    if mthDiff == 0:
        periodRangeSplitList.append((start,start))
        return periodRangeSplitList

    diff = mthDiff / intv
    print(diff)

    for i in range(intv):
        periodList.append ((start + diff * i).strftime("%Y%m"))
    periodList.append(end.strftime("%Y%m"))
    print(periodList)

我尝试了上面的代码，但不起作用，有人可以分享任何建议吗？

谢谢

Answer 1

使用简单的 while 循环怎么样？

def split_months(start, end, intv):
    from datetime import datetime
    from dateutil import relativedelta
    
    periodList = []

    start = datetime.strptime(start, '%Y%m')
    end = datetime.strptime(end, '%Y%m')
    step = relativedelta.relativedelta(months=intv-1)

    start_ = start
    while (end_:=start_+step) <= end:
        # add new period
        periodList.append((start_, end_))
        # update next start
        start_ = end_ + relativedelta.relativedelta(months=1)
    
    # convert output to string 
    return [(s.strftime('%Y%m'), e.strftime('%Y%m'))
            for s, e in periodList]

split_months('202307', '202612', 5)

输出:

[('202307', '202311'),
 ('202312', '202404'),
 ('202405', '202409'),
 ('202410', '202502'),
 ('202503', '202507'),
 ('202508', '202512'),
 ('202601', '202605'),
 ('202606', '202610')]

如果要将最后一个间隔添加到末尾，请更改 while 条件并添加额外的行 (periodList.append((start_, end)) ):

def split_months(start, end, intv):
    from datetime import datetime
    from dateutil import relativedelta
    
    periodList = []

    start = datetime.strptime(start, '%Y%m')
    end = datetime.strptime(end ,'%Y%m')
    step=relativedelta.relativedelta(months=intv-1)

    start_ = start
    while (end_:=start_+step) < end:
        periodList.append((start_, end_))
        start_ = end_ + relativedelta.relativedelta(months=1)
    periodList.append((start_, end))
    
    return [(s.strftime('%Y%m'), e.strftime('%Y%m'))
            for s,e in periodList]

示例:

# split_months('202307', '202612', 5)
[('202307', '202311'),
 ('202312', '202404'),
 ('202405', '202409'),
 ('202410', '202502'),
 ('202503', '202507'),
 ('202508', '202512'),
 ('202601', '202605'),
 ('202606', '202610'),
 ('202611', '202612')]

# split_months('202307', '202610', 5)
[('202307', '202311'),
 ('202312', '202404'),
 ('202405', '202409'),
 ('202410', '202502'),
 ('202503', '202507'),
 ('202508', '202512'),
 ('202601', '202605'),
 ('202606', '202610')]

# split_months('202307','202405',5)
[('202307', '202311'),
 ('202312', '202404'),
 ('202405', '202405')]