'Initializes this ParsedURL with an URL pattern value.
Args:
url_pattern: An URL pattern that conforms to the regular expression
Raises:
validation.ValidationError: When url_pattern does not match the required
regular expression.'

def __init__(self, url_pattern):

    split_matcher = _ValidateMatch(_URL_SPLITTER_RE, url_pattern, ("invalid    url    '%s'" % url_pattern))
    (self.host_pattern, self.path_pattern) = split_matcher.groups()
    if self.host_pattern.startswith('*'):
        self.host_exact = False
        self.host = self.host_pattern[1:]
    else:
        self.host_exact = True
        self.host = self.host_pattern
    if self.path_pattern.endswith('*'):
        self.path_exact = False
        self.path = self.path_pattern[:(-1)]
    else:
        self.path_exact = True
        self.path = self.path_pattern
