檢查 python function 中月份的有效性時出錯

Question

month_names=["january","february","march","april",
"may","june","july","august","september","october","november","december"]
day_in_month=[31,28,31,30,31,30,31,31,30,31,30,31]
date =" "
a,b=date.split(" ")


b=int()
x=False
def is_a_valid_date(date):
  global x
  for i in range(len(month_names)):
     if a==month_names[i]:
       if b<=day_in_month[i]:
           x=True
           print("h")
  return x     

 
print(is_a_valid_date("february 21"))

ValueError：沒有足夠的值來解包（預期 2，得到 1）
嘗試檢查輸入中的給定字符串是否是 month_names 中提到的有效月份如果與 day_in_month 中的天數相比，其后面的日期也有效

Answer 1

你應該避免使用 global 並且你根本不使用你的參數date ！

month_names = [
    "january","february","march","april",
    "may","june","july","august","september","october","november","december"
             ]
day_in_month = [31,28,31,30,31,30,31,31,30,31,30,31]


def is_a_valid_date(date):
  month, day = date.split(" ")  # split with space the month and day
  month_index = month_names.index(month)  # find the index of the month_index from the month_names
  day_as_int = int(day)  # convert the day to int for compering
  return day_as_int <= day_in_month[month_index] # check if it bigger

 
print(is_a_valid_date("february 29")) # False
print(is_a_valid_date("february 28")) # True

如果你想捕捉大寫和磨損輸入等邊緣情況：

month_names = [
    "january","february","march","april",
    "may","june","july","august","september","october","november","december"
             ]
day_in_month = [31,28,31,30,31,30,31,31,30,31,30,31]


# make it lower case
def is_a_valid_date(date):
    try:
        month, day = date.lower().split(" ")  # split with space the month and day
        month_index = month_names.index(month)  # find the index of the month_index from the month_names
        day_as_int = int(day)  # convert the day to int for compering
        return day_as_int > 0 and day_as_int <= day_in_month[month_index] # check if it bigger
    except ValueError:
        return False
 
print(is_a_valid_date("february 29")) # False
print(is_a_valid_date("february 28")) # True
print(is_a_valid_date("febGuary 28")) # False
print(is_a_valid_date("february 0")) # False
print(is_a_valid_date("February 1")) # True
print(is_a_valid_date("February1")) # False
print(is_a_valid_date("February gasf")) # False
print(is_a_valid_date("")) # False

Answer 2

嘗試這個：

month_names=["january","february","march","april",
"may","june","july","august","september","october","november","december"]
day_in_month=[31,28,31,30,31,30,31,31,30,31,30,31]

x=False
def is_a_valid_date(date):
  global x
  a,b=date.split(" ")
  for i in range(len(month_names)):
     if a==month_names[i]:
       if int(b)<=day_in_month[i]:
           x=True
           print("h")
  return x     

 
print(is_a_valid_date("february 21"))

Output：

h
True

Answer 3

如果你有年份和月份，你可以使用calendar.monthrange(int year, int month)來獲取當月的天數

https://docs.python.org/3/library/calendar.html#calendar.monthrange

import calendar
_, days_in_month = calendar.monthrange(2021, 1)
# days_in_month = 31

您應該重構以使用它，因為它也將在沒有額外條件/數據集的情況下正確考慮閏年