def except_on_missing_scheme(url):
 (scheme, netloc, path, params, query, fragment) = urlparse(url)
 if (not scheme):
  raise MissingSchema('Proxy URLs must have explicit schemes.')

def except_on_missing_scheme ( url ) : ( scheme , netloc , path , params , query , fragment ) = urlparse ( url ) if ( not scheme ) : raise MissingSchema ( 'Proxy URLs must have explicit schemes.' )
given a url .