def mapping_keys(s):
 mapping_keys_re = re.compile('\\%\\([^\\)]*\\)\\w')
 return sorted(mapping_keys_re.findall(s))

def mapping_keys ( s ) : mapping_keys_re = re . compile ( '\\%\\([^\\)]*\\)\\w' ) return sorted ( mapping_keys_re . findall ( s ) )
return a sorted list of the mapping keys in the string s .