Python-chain.from_iterable返回内存地址而不是值

Question

I'm trying to write a simple program for taking in a set of elements and printing out the powerset.

I'm using the recipe for a powerset function as given in python's documentation: https://docs.python.org/3.4/library/itertools.html

For some reason instead of returning values, it returns the memory address of a itertools.chain object.

Why is it doing this?

from itertools import chain,combinations
def pwrst(iter):
    xs = list(iter)
    return chain.from_iterable( combinations(xs,n) for n in range(len(xs)+1))
s = input("Enter elements seperated by comma: ")
il = s(',')
ss = [int(x.strip()) for x in il]
pwrst(ss)

Answer 1

chain.from_iterable returns an iterable object (whose default __repr__ tells you the memory address). You actually have to iterate over it to get the values. eg:

list(pwrst(ss))

Under normal circumstances, you might do something like:

for item in pwrst(ss):
    ...