File Searcher - Python Code Bank

                from UserList import UserList
from os import listdir, curdir
from os.path import isfile, isdir
from os.path import join as joinpath
from os.path import split as splitpath
#version 0.7
class filespider:
    def __init__(self,action,verbose=False):
        self.verbose=verbose
        self.action=action
    def __scanpath(self,path):
        if self.verbose:print "scanning:"+path
        try:
            items=listdir(path)
            for item in items:
                itempath=joinpath(path,item)
                self.action(itempath)
                if isdir(itempath):
                    if not itempath in self.pastpaths:
                        self.futurepaths.append(itempath)
        except WindowsError:
            print 'WindowsError encountered at:'+path
        self.pastpaths.append(path)
    def start(self,root):
        self.pastpaths=[]
        self.futurepaths=[]
        if not isdir(root):
            print "that's not a directory!"
            return -1
        print "scanning"
        print root
        self.futurepaths.append(root)
        while self.futurepaths:
            self.__scanpath(self.futurepaths.pop())
        print 'scan complete'
class filterlist(UserList):#a list which is filtered by a given function
    def __init__(self, filterfunction,initlist=None):
        self.data = []
        initlist=None
        self.function=filterfunction
    def append(self, item):
        if self.function(item):
            self.data.append(item)
    def insert(self, i, item):
        if self.function(item):
            self.data.insert(i, item)
def isfoundin(keyword, string, capsense=False):
    return keyword.lower() in string.lower()
rootpath=raw_input("Root path to begin searching at:")
keyword=raw_input("Keyword to search for:")
MyHits=filterlist(lambda x:isfoundin(keyword,splitpath(x)[-1]))
#note the use of lambda here. filterlist will pass one arguement,
#but isfoundin requires two. there must be a better way, but this works.
FileCrawler=filespider(MyHits.append)
FileCrawler.start(rootpath)
for i in MyHits:
    print i