# test permutations and combinations
import itertools as it
for i in it.combinations('abcd',2):
print (i)
for j in it.combinations('123456',4):
print (j)
for k in it.permutations('ABCDEF',2):
print (k)
for m in it.product('ZXY','1234'):
print (m)
lists = ['a','b','c']
print (list(itertools.permutations(lists,2)))#排列,和顺序有关
print ('='*60)
print (list(itertools.combinations(lists,2)))#组合,和顺序无关