Show error information in Python

This code uses a while loop and a try-except block to get a valid integer input from the user.

The while loop will continue to run indefinitely until the user provides a valid integer input.

Inside the while loop, the code uses a try-except block to try to convert the user’s input to an integer using the int() function. If the user’s input is not a valid integer, a ValueError will be raised.

In case a ValueError is raised, the code inside the except block will be executed. The code inside the except block first prints the message “invalid number, please try again” and then prints the error message contained in the exception object e using print(e).

The loop will continue to run until a valid integer is entered by the user. Once a valid integer is entered, the break statement will be executed and the loop will exit.

Finally, the code outside the loop prints the message “go on”.

The try-except block allows the code to continue executing even in the presence of errors, without crashing the program. It provides a way to handle exceptions and provides a more user-friendly output, in this case, prompting the user to try again until a valid integer is entered.

while True:
    try:
        userInput = int(input("Please enter a number: "))
        break
    except ValueError as e:
        print("invalid number, please try again", e)
print("go on")

Output

Please enter a number: g
invalid number, please try again invalid literal for int() with base 10: 'g'
Please enter a number: 5.6
invalid number, please try again invalid literal for int() with base 10: '5.6'
Please enter a number: 5
go on