Practice: Validate Age

This exercise combines try/except and raise in one function — the shape of most input validation: convert, check, and raise with a clear message when the input is unusable.

Exercise

1. Define a function named validate_age with one parameter, text.
2. Convert text to an int. If the conversion fails, raise ValueError with the message age must be a whole number.
3. If the number is below 0 or above 120, raise ValueError with the message age out of range.
4. Otherwise return the number.

validate_age("42") returns 42. validate_age("abc") and validate_age("130") both raise ValueError.

Run your code to see the output, then press Submit.

Hints

• Catch the ValueError from int(text) and raise your own with the required message.
• Do the range check after the conversion, outside the try.

Tests

import unittest


class TestValidateAge(unittest.TestCase):
    def test_valid_age(self):
        self.assertEqual(validate_age("42"), 42)

    def test_zero_is_valid(self):
        self.assertEqual(validate_age("0"), 0)

    def test_letters_raise_with_message(self):
        with self.assertRaises(ValueError) as context:
            validate_age("abc")
        self.assertEqual(str(context.exception), "age must be a whole number")

    def test_negative_age_raises_with_message(self):
        with self.assertRaises(ValueError) as context:
            validate_age("-1")
        self.assertEqual(str(context.exception), "age out of range")

    def test_130_raises_with_message(self):
        with self.assertRaises(ValueError) as context:
            validate_age("130")
        self.assertEqual(str(context.exception), "age out of range")