Finds out whether there are intervals to expand and
    creates the charset

def parse_charset(charset):
    """
    Finds out whether there are intervals to expand and
    creates the charset
    """
    import re
    regex = r'(\w-\w)'
    pat = re.compile(regex)
    found = pat.findall(charset)
    result = ''
    if found:
        for element in found:
            for char in char_range(element[0], element[-1]):
                result += char
        return result
    return charset