#Input
t = ['pid', 'sn', 'uuid', 'host_id']
# Expected output
[('pid'),('sn'),('uuid'),('host_id'),('pid','sn'),('pid','uuid'),('pid','host_id'),('sn','uuid'),('sn','host_id',('uid','host_id'))]
I want to extract single values first and then extract the combination without duplicates.
For e.g. ('pid','sn') and ('sn','pid') are same. I want only one value. I tried permutations in itertools but it is returning all the matches.
Answer
You must use combinations instead of permutations:
import itertools
t = ['pid', 'sn', 'uuid', 'host_id']
result = []
for n in range(1, len(t)+1):
for res in itertools.combinations(t, n):
result.append(res)
result
output:
[('pid',),
('sn',),
('uuid',),
('host_id',),
('pid', 'sn'),
('pid', 'uuid'),
('pid', 'host_id'),
('sn', 'uuid'),
('sn', 'host_id'),
('uuid', 'host_id'),
('pid', 'sn', 'uuid'),
('pid', 'sn', 'host_id'),
('pid', 'uuid', 'host_id'),
('sn', 'uuid', 'host_id'),
('pid', 'sn', 'uuid', 'host_id')]