filter

   str = ['a','b','c','d']
   def fun1(s): return s if s != 'a' else None
   ret = fileter(func,str)
   print ret

map

   str = ['a','d']
   def func2(s): return s + '.txt'
   ret = map(fun2,str)
   print ret

reduce

   def adda(x,y): return x + y
   print reduce(ass1,range(1,100))
   print reduce(ass1,100),20)

lambda

   g = lambda s: s + '.fsh'
   print g('haha')
   print (lambda x: x*2)(3)