How Do I Check If The User Has Entered A Number?

I making a quiz program using Python 3. I'm trying to implement checks so that if the user enters a string, the console won't spit out errors. The code I've put in doesn't work, an

Solution 1:

You need to catch the exception already in the first if clause. For example:

for _ inrange(num_of_q):
    num1=random.randint(0,10)
    num2=random.randint(1,10)
    op,symbol=random.choice(operation)
    print("What is",num1,symbol,num2,"?")
    try:
        outcome = int(input())
    except ValueError:
        print("That's not a number!")
    else:
        if outcome == op(num1, num2):
            print("Correct")
            score += 1else:
            print("Incorrect")

I've also removed the val = int(input()) clause - it seems to serve no purpose.

EDIT

If you want to give the user more than one chance to answer the question, you can embed the entire thing in a while loop:

for _ inrange(num_of_q):
    num1=random.randint(0,10)
    num2=random.randint(1,10)
    op,symbol=random.choice(operation)
    whileTrue:
        print("What is",num1,symbol,num2,"?")
        try:
            outcome = int(input())
        except ValueError:
            print("That's not a number!")
        else:
            if outcome == op(num1, num2):
                print("Correct")
                score += 1breakelse:
                print("Incorrect, please try again")

This will loop eternally until the right answer is given, but you could easily adapt this to keep a count as well to give the user a fixed number of trials.

Solution 2:

Change

print("What is",num1,symbol,num2,"?")
ifint(input()) == op(num1, num2):

to

print("What is",num1,symbol,num2,"?")
user_input = input()
ifnot user_input.isdigit():
    print("Please input a number")
    # Loop till you have correct input typeelse:
    # Carry on

The .isdigit() method for strings will check if the input is an integer. This, however, will not work if the input is a float. For that the easiest test would be to attempt to convert it in a try/except block, ie.

user_input = input()
try:
    user_input = float(user_input)
except ValueError:
    print("Please input a number.")