python code(1)

 from collections import UserList

 class MthChianList(UserList):

     def filter(self,predicste):

         return MthChianList(elem for elem in self if predicste(elem))

     def map(self,mapper):

         return MthChianList(mapper(elem) for elem in self)

     def for_each(self,action):

         for elem in self:

             action(elem)

 lt=MthChianList(['A','B','c','d','e','F'])

 lt.filter(str.islower).map(str.upper).for_each(print)