输入为一串日期的长字符串，每个日期之间使用 "," 分隔开。
days_str = '''2021-11-17,2021-11-19,2021-11-20,2021-11-21,2021-11-23'''
统计连续出现日期的最大天数。
def calculate_consecutive_dates(dates_str: str):
max_consecutive_days = 0
temp_flag = 0
dates_list = dates_str.split(",")
dates = [datetime.strptime(d, "%Y-%m-%d") for d in dates_list]
date_ints = [d.toordinal() for d in dates]
retlist = list()
count = 1
# Avoid Index Error
for i in range(len(date_ints) - 1):
# Check if the next number is consecutive
if date_ints[i] + 1 == date_ints[i + 1]:
count += 1
else:
# If it is not append the count and restart counting
retlist.append(count)
count = 1
# In case we stop the loop earlier then we should append the last count
retlist.append(count)
retlist.sort(reverse=True)
return retlist[0]
关键函数：
dates_list = dates_str.split(",") # 将字符串以某个分隔符分开，并返回一个list
dates = [datetime.strptime(d, "%Y-%m-%d") for d in dates_list] # 将字符串以特定形式转换为日期型数据
date_ints = [d.toordinal() for d in dates] # d.toordinal() 将日期转换为一个正整数。
# 动态编程进行运算
retlist = list()
count = 1
# Avoid Index Error
for i in range(len(date_ints) - 1):
# Check if the next number is consecutive
if date_ints[i] + 1 == date_ints[i + 1]:
count += 1
else:
# If it is not append the count and restart counting
retlist.append(count)
count = 1
# In case we stop the loop earlier then we should append the last count
retlist.append(count)
retlist.sort(reverse=True)
return retlist[0]
