How to a ValueError Input and Use It (Python 3.7)

Question

This is my code for my Computer Science class. I added a feature to make sure the user does not enter a non-int/float. I am trying to access what the users entry to repeat it so it goes like this:

Enter your first number:
> not_a_valid_float_or_int
"not_a_valid_float_or_int" is not a valid number, try again.

So basically I am trying to replace "What you have entered" with what the user had entered.

print("Hello!\n")
while True:
    try:
        firstnumber = float(input("Enter your first number:\n"))
    except ValueError:
        print("\nWhat you have entered is not a valid number, try again.")
    else:
        break
print()
while True:
    try:
        secondnumber = float(input("Enter your second number:\n"))
    except ValueError:
        print("\nWhat you have entered is not a valid number, try again.")
    else:
        break
print("\nThe first number is:", str(firstnumber).rstrip("0").rstrip(".") , "\nThe second number is:", str(secondnumber).rstrip("0").rstrip("."), "\nThe sum is:", str(firstnumber + secondnumber).rstrip("0").rstrip("."), "\nThe product is:", str(firstnumber * secondnumber).rstrip("0").rstrip("."))

Thanks a lot!

David

P.S. please know that I am very knew to the coding scene.

Store the input string as a variable outside the try/except blocks, then try to use float(), and if an error is caught then you can use that string in the error printing. — burgerhex
– burgerhex, Commented Oct 12, 2018 at 0:01

YiFei · Accepted Answer · 2018-10-12 00:27:19Z

1

To give you an idea of what the comment means,

while True:
    firstnumber_raw = input("Enter your first number:\n")
    try:
        firstnumber = float(firstnumber_raw)
    except ValueError:
        print("\n'" + firstnumber_raw "' is not a valid number, try again.")
    else:
        break

As a side note, since you tagged Python 3.7, f-string is your friend.

answered Oct 12, 2018 at 0:27

YiFei

1,8781 gold badge20 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to a ValueError Input and Use It (Python 3.7)

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related