为什么我的脚本不接受有效日期作为用户输入？

Question

The script works fine if I give it a date of 01/12/2021 . But if I give it another date like today's as 01/18/2021 or any other the script says that the date isn't valid and prompts the user to enter the date in again.

def print_reports(interactive,aws_account,aws_account_number):
    inputDate = input("Enter the date in format 'dd/mm/yyyy': ")
    day,month,year = inputDate.split('/')
    isValidDate = True
    try:
        datetime(int(year),int(month),int(day))
    except ValueError :
        isValidDate = False
        print("Date is not valid.")
        print_reports(interactive,aws_account,aws_account_number)

    if(isValidDate) :
        print(f"Input date is valid: {inputDate}")
        format= "%m%d%Y"
        inputDate = datetime.strptime(inputDate,"%m/%d/%Y")
        inputDate = inputDate.strftime(format)
    else:
        print(f"Input date is not valid: {inputDate}")
        print_reports(interactive,aws_account,aws_account_number)
    myclient = connect_db()
    mydb = myclient["aws_inventories"]
    instance_col = "ec2_list_" + inputDate
    instance_col = mydb[instance_col]
    print_reports(interactive,aws_account,aws_account_number)

This is the output I get if I put in some different dates:

Enter the date in format 'dd/mm/yyyy': 01/12/2021
Input date is valid: 01/12/2021
Enter the date in format 'dd/mm/yyyy': 01/13/2021
Date is not valid.
Enter the date in format 'dd/mm/yyyy': 01/14/2021
Date is not valid.
Enter the date in format 'dd/mm/yyyy': 01/15/2021
Date is not valid.
Enter the date in format 'dd/mm/yyyy': 01/16/2021
Date is not valid.

Why won't my script accept any date other than 01/12/2021 as valid input?

Answer 1

01/16/2021 is not a valid date, since the year has only 12 months and not 16;).
Your code should be like this:

def print_reports(interactive, aws_account, aws_account_number):
    inputDate = input("Enter the date in format 'dd/mm/yyyy': ")
    day, month, year = inputDate.split('/')
    try:
        datetime(int(day), int(month), int(year))
    except ValueError as e:
        print("Date is not valid.")
        return False

    print(f"Input date is valid: {inputDate}")
    inputDate = datetime.strptime(inputDate,"%d/%m/%Y")
    return True
myclient = connect_db()
mydb = myclient["aws_inventories"]
instance_col = mydb["ec2_list_" + inputDate]
while not success:
    global success
    success = print_reports(interactive, aws_account, aws_account_number)

Answer 2

You are asking for the format dd/mm/yyyy . Yet, you are inputting (in what I assume) is a mm/dd/yyyy format. If you try to parse 01/18/2021 in the format dd/mm/yyyy , then you would get the result that it is the first day in the 18th month in the year 2021 (which, of course, is impossible - there are only 12 months in the year). To fix this, you are going to either have to change your format to mm/dd/yyyy or input as 18/01/2021 .

To change the input checker to mm/dd/yyyy :

def print_reports(interactive, aws_account, aws_account_number):
    inputDate = input("Enter the date in format 'mm/dd/yyyy': ")
    month, day, year = inputDate.split('/') # changed order of month and day
    isValidDate = True
    try:
        datetime(int(year), int(month), int(day))
    except ValueError:
        isValidDate = False
        print("Date is not valid.")
        print_reports(interactive, aws_account, aws_account_number)

    if isValidDate:
        print(f"Input date is valid: {inputDate}")
        format = "%m%d%Y"
        inputDate = datetime.strptime(inputDate,"%m/%d/%Y")
        inputDate = inputDate.strftime(format)
    else:
        print(f"Input date is not valid: {inputDate}")
        print_reports(interactive,aws_account,aws_account_number)
    myclient = connect_db()
    mydb = myclient["aws_inventories"]
    instance_col = "ec2_list_" + inputDate
    instance_col = mydb[instance_col]
    print_reports(interactive,aws_account,aws_account_number)

Note that it looks like you are using the function datetime with the dd/mm/yyyy format, but you are using the mm/dd/yyyy format with datetime.strptime in the original code. In this code, it only uses the mm/dd/yyyy format, but you can always edit this easily to dd/mm/yyyy .

Edit: Looks like you are using recursion. Of course, instead, you should be using a while loop, as recursion is not needed here. Also, you are using the isValidDate variable, but that is never actually used or needed:

def print_reports(interactive, aws_account, aws_account_number):
    while True:
        inputDate = input("Enter the date in format 'mm/dd/yyyy': ")
        month, day, year = inputDate.split('/') # changed order of month and day
        try:
            datetime(int(year), int(month), int(day))
        except ValueError:
            print("Date is not valid.")
            continue

        print(f"Input date is valid: {inputDate}")
        format = "%m%d%Y"
        inputDate = datetime.strptime(inputDate,"%m/%d/%Y")
        inputDate = inputDate.strftime(format)

        myclient = connect_db()
        mydb = myclient["aws_inventories"]
        instance_col = "ec2_list_" + inputDate
        instance_col = mydb[instance_col]