How to use the ValueError ExceptionType in Python for Function Input Validation

The aim of this page📝 is to add a small usecase for ValueError Exception type in python. For example

def validate_and_capitalize(section_name: str, section_folders: list) -> str:
    if not re.match(r"\d\d\s.*", section_name):
        raise ValueError(f"The first 2 characters need to be a sectionID, e.g. 66")
    # ...

• The idiomatic use is to start function with input validation
• Raise handled exception with ValueError and description of what is wrong
• Typical methods are isalpha(), isdigit(), in operator and len() of the input
• Given a string representing one Unicode character, return an integer representing the Unicode cod
• This is from a lesson I am currently taking

def create(owner_code, serial, category='U'):
    """Create an ISO 6346 shipping container code.

    Args:
        owner_code (str): Three character alphabetic container code.
        serial (str): Six digit numeric serial number.
        category (str): Equipment category identifier.

    Returns:
        An ISO 6346 container code including a check digit.

    Raises:
        ValueError: If incorrect values are provided.
    """
    if not (len(owner_code) == 3 and owner_code.isalpha()):
        raise ValueError("Invalid ISO 6346 owner code '{}'".format(owner_code))

    if category not in ('U', 'J', 'Z', 'R'):
        raise ValueError("Invalid ISO 6346 category identifier '{}'".format(category))

    if not (len(serial) == 6 and serial.isdigit()):
        raise ValueError("Invalid ISO 6346 serial number")
    # ...