How would using a try and except block help us validate user inputs if the input needsto be casted to a numeric data type, such as an int?
Question
How would using a try and except block help us validate user inputs if the input needs to be casted to a numeric data type, such as an int?
Solution
Using a try and except block can be very useful in validating user inputs that need to be casted to a numeric data type, such as an int. Here's how you can do it step by step:
-
Ask for User Input: First, you would ask the user for input using the
input()
function in Python. This function returns the user input as a string. -
Try Block: You would then use a try block to attempt to cast the user input to an integer using the
int()
function. If the user input is a string that can be converted to an integer, this operation will be successful and the program will continue. -
Except Block: If the user input is a string that cannot be converted to an integer (for example, if the user enters a word or a decimal number), the
int()
function will raise aValueError
. You can catch this error using an except block. In the except block, you can print an error message to the user and ask them to enter a valid integer. -
Loop Until Valid Input: To ensure that the program continues to ask for input until the user enters a valid integer, you can put the try and except block inside a while loop. The loop will continue until the user input is successfully casted to an integer, at which point you can use a
break
statement to exit the loop.
Here's an example of what this might look like in code:
while True:
user_input = input("Please enter an integer: ")
try:
user_input = int(user_input)
break
except ValueError:
print("That's not a valid integer. Please try again.")
In this code, if the user enters a valid integer, the input will be casted to an int and the loop will break. If the user enters an invalid input, a ValueError
will be raised, the error message will be printed, and the loop will continue, asking the user for input again.
Similar Questions
Which of the following should immediately follow ‘try’ block to handle an exception? finally catch else except
Select the correct answerWhich of the given blocks is used to handle the exceptions generated by the try block?Optionstrythrowcheckcatch
What is the role of the else and finally blocks in exception handling, and how do they differ from the try and except blocks?
Which block lets you test a block of code for errors?tryexceptfinallyNone of the above
When will the else part of try-except-else be executed?alwayswhen an exception occurswhen no exception occurswhen an exception occurs in to except block
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