def count_digits(text: str) -> int:
    counter = 0
    for element in text:
        if element.isdigit():
            counter += 1
    return counter


if __name__ == "__main__":
    print("Example:")
    print(count_digits("hi"))

    # These "asserts" are used for self-checking and not for an auto-testing
    assert count_digits("hi") == 0
    assert count_digits("who is 1st here") == 1
    assert count_digits("my numbers is 2") == 1
    assert (
        count_digits(
            "This picture is an oil on canvas painting by Danish artist Anna Petersen between 1845 and 1910 year"
        )
        == 8
    )
    assert count_digits("5 plus 6 is") == 2
    assert count_digits("") == 0
    print("Coding complete? Click 'Check' to earn cool rewards!")
