import re
def build_match_and_apply_functions(pattern, search, replace):

   def matches_rule(word):

      return re.search(pattern, word)

   def apply_rule(word):

      return re.sub(search, replace, word)

   return (matches_rule, apply_rule)
patterns = \
(
('[sxz]$', '$', 'es'),
('[^aeioudgkprt]h$', '$', 'es'),
('(qu|[^aeiou])y$', 'y$', 'ies'),
('$', '$', 's')
)
rules = [build_match_and_apply_functions(pattern, search, replace)
         for (pattern, search, replace) in patterns]
def plural(noun):
   for matches_rule, apply_rule in rules:
      if matches_rule(noun):
         return print(apply_rule(noun))