How would I put ValueError as a procedure and use it to check the age and firstname?

Question

How would I use that errorcheck procedure throughout my program so I can check whether or not the user has inputted the correct data type?

def errorcheck():
    valid=False
    while valid==False:
        try:
            ()=True
        except ValueError:
            print("Please enter an appropriate value")
            valid=False

errorcheckage=int(input("How old are you?"))
forename=str(input("What is your firstname?"))
username=forename[0:3]+age
print(username)

Possible duplicate of [Determine the type of an object?](https://stackoverflow.com/questions/2225038/determine-the-type-of-an-object) — Mangohero1, Oct 04 '17 at 15:53
How would I do this? Only need to put in to get extra marks in an assessment that requires the program to be robust — Charlie Hutty, Oct 04 '17 at 16:04
use `isinstance`. put all of your inputs inside your `try` block — Mangohero1, Oct 04 '17 at 16:23

score 0 · Answer 1 · answered Oct 04 '17 at 16:15

You can write a wrapper that implements your loop controls, but it's rather detailed and may not save you much time.

def validator_loop(f: "function to run",
                   *args: "arguments to function",
                   validator=lambda _: True,
                   **kwargs: "kwargs for function"):
    while True:
        try:
            result = f(*args, **kwargs)
        except Exception as e:
            continue  # repeat if it throws any exception
        else:
            if validator(result):
                return result

# note that an entry of "zero" will fail this validation, even though
# 0 is a valid age for some purposes! I'll leave this edge case for you
checkage = validator_loop(input, "How old are you?",
                          validator=lambda s: int(s))

How would I put ValueError as a procedure and use it to check the age and firstname?

1 Answers1