在Python中生成长度可变的随机连续日期

Question

我想在给定的时间范围内产生随机的连续日期。我已经看到了一些生成随机日期的方法，下面我尝试了一个函数，但是我认为有一种更紧凑的方法来实现它。任何帮助都是非常感谢的！

这个函数做了几件事：

1. 从日期窗口中的随机起点创建连续日期。
2. 这些连续日期的可变长度在2-5天之间。
3. 该函数确保在给定的开始日期和结束日期之间选择连续日期。

代码在下面。是否有一种更紧凑的方法来生成这个函数？

def illness(start_date,end_date):
  funct_ill_list=[]   #list that will store all dates 

  #randomly choosing first date
  diff = end_date - start_date
  random_number = random.randint(0,diff.days-5)  
 
  
  temp = start_date + datetime.timedelta(random_number)    #temp = 1 march + "random_number" days 
  funct_ill_list.append(temp)                              #adding the first date to list

  
  #adding next 'n' (2-5) consecutive dates after our last element in list(most recently added date in list)
  # ----------------FOR EXAMPLE - funct_ill_list = ['4 march','5 march','6 march']; random_number=3
 
  while funct_ill_list[-1]<=end_date:                              #stop when last element in list (most recently added date in list) exceeds end_date
      random_number = random.randint(2,5)                           #for 2-5 random days (consecutive) - get a random integer between 2 to 5
      last = funct_ill_list[-1]+datetime.timedelta(random_number)   #'last' variable stores maximum possible date we will have with chosen random_number
      if last>end_date:   
        funct_ill_list.pop()
        break
      else:                                          #else add next 'random_number' dates to list
        ref_date = funct_ill_list[-1]                #last element of list
        for i in range(1,random_number):             #'i' takes values from 1 to (random_number-1).
          temp = ref_date + datetime.timedelta(i)    #each time add 'i' days to ref_date to get new date 'temp'
          funct_ill_list.append(temp)                #add this new date to list.
      
      #for next random date
      # --------------FOR EXAMPLE - funct_ill_list = ['4 march','5 march','6 march','25 march']
      diff = end_date - funct_ill_list[-1]                        #get no. of days remaining b/w end_date and last element added to list
      if diff.days>=2:                                            #if diff.days=0 or 1, ie. last element in list is either end_date or end_date-1,
                                                                  #No point of adding more dates for next round (since 2-5 consecutive days won't be possible), else add.
       
        random_number = random.randint(2,diff.days)                   #randomly choose a number
        temp = funct_ill_list[-1] + datetime.timedelta(random_number) #adding "random_number" days to last element of list
        funct_ill_list.append(temp)                                   #adding it to list
  return funct_ill_list



ill_start_date = datetime.date(2020, 2, 1)
ill_end_date = datetime.date(2020, 4, 30)
month_time_frame = [3,5] #static two months time frame (Looks at matching dates in March and May months)

Answer 1

如果日期不符合条件，则不需要太多的迭代和删除日期，因为这里没有太多的随机性。你只需要两个随机数：

• 你的回报值是多少天？让我们将其称为m，这是范围[2, 5]中的一个整数。
• 在start_date-end_date间隔中，我们应该开始我们的日期序列吗？或者，我们的第一次约会应该在start_date之后几天？让我们称其为N。

很容易注意到，N受给定开始结束范围内的天数(我们称之为R)和疾病持续时间(m)的限制。具体来说，我们知道N <= R - m。

一旦我们有了N，我们就知道我们想要的日期是：

• start_date + N日
• start_date + N + 1日
• ..。等等..。
• start_date + N + m - 1日

这可以使用start_date + range(N+m) days的简单循环或列表理解来生成。

import random
import datetime

def illness(start_date, end_date):
    # Duration of start-end range (R)
    max_days = (end_date - start_date).days

    # How many days should the illness start (m)
    illness_days = random.randint(2, min(max_days, 5))

    # Number of days after start_date that the first random date is on (N)
    illness_start = random.randint(0, max_days - illness_days)

    # Make a list of illness_days consecutive dates starting from the first illness day
    illness_dates = [start_date + datetime.timedelta(days=illness_start + d) for d in range(illness_days)] 

    return illness_dates

运行此命令：

sd = datetime.date(2021, 1, 1)
ed = datetime.date.today()
illness(sd, ed)

提供随机(在本例中为4)在给定间隔内随机设置的连续日期数：

[datetime.date(2021, 4, 26),
 datetime.date(2021, 4, 27),
 datetime.date(2021, 4, 28),
 datetime.date(2021, 4, 29)]