import re


def get_class_name(a_string):
    """Convert a name string to format: ThisIsAnUnusualName.
    Take a space delimited string, return a class name such as ThisIsAnUnusualName
    Here we use this function for instance name. Thus it allows to start with a number
    """
    joint_name = a_string.title().replace(' ', '')
    # substitute except for  _, character, number
    non_legitimate = re.compile(r'[\W]+')
    class_name = non_legitimate.sub('', joint_name)
    return class_name