以 ISO 周频率获取 2020 年的所有开始日期

Question

我想创建一个日期列表，每个日期代表 2020 年 ISO 第 N 周的开始日期。

类似于：

weeks2020 = [date(2020, 1, 1), date(2020, 1, 6), date(2020, 1, 13), ...]

我使用 timedelta(weeks=1) 获得了类似的东西，并将其添加到我的 START_DATE (date(2020, 1, 1))，但我获得的日期不正确。

我知道我可以简单地将 START_DATE 更改为 date(2019, 12, 30)，但我想知道是否有更可靠的方法来推导给定年份中出现的所有周开始日期.

为了清楚起见，这是我现在正在做的事情：

from datetime import date, timedelta

START_DATE = date(2020, 1, 1)
INTERVAL = timedelta(weeks=1)
STEPS = 54

prev_date = START_DATE

for i in range(1, STEPS):
    print(prev_date.strftime('%Y-%m-%d')) # step 1: 2020-01-01, step 2: 2020-01-08, ...
    prev_date += INTERVAL

Answer 1

试图回答自己。

我不知道这是否是最佳解决方案，但它似乎很适合我的目标：

from datetime import date, timedelta

START_DATE = date(2020, 1, 1)
INTERVAL = timedelta(days=1)
STEPS = 366

iso_week = 0

weeks_2020 = []

curr_date = START_DATE

for d in range (STEPS):
    if not curr_date.isocalendar()[1] == iso_week:
        iso_week = curr_date.isocalendar()[1]
        weeks_2020.append(curr_date)
    curr_date += INTERVAL

Answer 2

如果你能用pandas，也许这样的东西应该是可行的-

import pandas as pd

di = pd.to_datetime(pd.date_range(start='2020-1-1', end='2020-12-31', freq='D'))
# check for either monday or start of the month
weekstart = di[(di.weekday == 0) | ((di.day == 1) & (di.weekday != 6)]

输出

DatetimeIndex(['2020-01-01', '2020-01-06', '2020-01-13', '2020-01-20',
               '2020-01-27', '2020-02-01', '2020-02-03', '2020-02-10',
               '2020-02-17', '2020-02-24', '2020-03-02', '2020-03-09',
               '2020-03-16', '2020-03-23', '2020-03-30', '2020-04-01',
               '2020-04-06', '2020-04-13', '2020-04-20', '2020-04-27',
               '2020-05-01', '2020-05-04', '2020-05-11', '2020-05-18',
               '2020-05-25', '2020-06-01', '2020-06-08', '2020-06-15',
               '2020-06-22', '2020-06-29', '2020-07-01', '2020-07-06',
               '2020-07-13', '2020-07-20', '2020-07-27', '2020-08-01',
               '2020-08-03', '2020-08-10', '2020-08-17', '2020-08-24',
               '2020-08-31', '2020-09-01', '2020-09-07', '2020-09-14',
               '2020-09-21', '2020-09-28', '2020-10-01', '2020-10-05',
               '2020-10-12', '2020-10-19', '2020-10-26', '2020-11-02',
               '2020-11-09', '2020-11-16', '2020-11-23', '2020-11-30',
               '2020-12-01', '2020-12-07', '2020-12-14', '2020-12-21',
               '2020-12-28'],
              dtype='datetime64[ns]', freq=None)

Answer 3

对于第一个间隔，找到开始日期的工作日并将其从整周中减去。第一步后，将间隔设置回一周。

START_DATE = date(2020, 1, 1)
INTERVAL = timedelta(weeks=1) - timedelta(days=START_DATE.weekday())

cur_date = START_DATE

while cur_date.year == START_DATE.year:
    print(cur_date.strftime("%Y-%m-%d"))
    cur_date += INTERVAL
    INTERVAL = timedelta(weeks=1)

以 ISO 周频率获取 2020 年的所有开始日期

Getting all starting dates of year 2020 with ISO week frequency

python

datetime

calendar

week-number

python-3.x