def capitalise_first_letter(old_string):
    """
    Really simple method to capitalise the first character of a string.

    Args:
        old_string: The string to be capitalised
    Returns:
        new_string: The capitalised string
    """

    if len(old_string) > 0:
        return old_string[0].upper() + old_string[1:]
    else:
        return old_string