class_extensions.py

class Mappable:
    def __init__(self, items): self.items = items
    def map(self, func):
        return self.__class__(map(func, self.items))

class Filterable:
    def __init__(self, items): self.items = items
    def filter(self, func):
        return self.__class__(filter(func, self.items))

class Hosts(object, Mappable, Filterable):
    def __init__(self, items):
        super(Hosts, self).__init__()
        self.items = items

hosts = Hosts(["one", "two", 1337])
print hosts\
    .filter(lambda x: type(x) == str)\
    .filter(lambda x: not x.startswith("one"))\
    .map(lambda x: {x: x*2})\
    .items
print hosts