permutations of a long list breaks memory

Question

#!/usr/bin/python                                                                                                                          

import itertools

list1 = ['XTN','XES','XSD','XRT','XLI','XME','XLE','XLF','XAR','XLB','XHE','XLK','XLY','XHB','XBI','XLP','XLV','XPH','XLU']

perm = list(itertools.permutations(list1))

print(perm)

Hi, the above code gets a "Killed" on a good sized instance or station and it's running time is unacceptable anyway.

My question is, for the given list, I would like to permute the arrangements but to produce all,so for example, "A", "B", "C"

A
B
C
AB
AC
BC

And so on - anyone have code which can do that for an arbitrary list and not squash the machine?

Answer 1

itertools.permutations() returns a generator, so you could just... not convert it to a list.

list1 = ['XTN','XES','XSD','XRT','XLI',...]
permutations = itertools.permutations(list1)
for permutation in permutations:
  print(permutation)