To generate all possible combinations of items in a list and STORE them in different lists, and to access them later. I have stated an example below - python-3.x

Question

# To generate possible combinations
from itertools import combinations
main_list=('a1','a2','a3','a4')
abc=combinations(main_list,3)
for i in list(abc):
print(i)
# Creating number of empty lists
n=6
obj={}
for i in range(n):
obj['set'+str(i)]=()
# I want to combine these, take list1 generated by combinations and store them down in set1.
/* To generate all possible combinations of items in a list and STORE them in different lists. Eg: main_list=('a1','a2','a3'), now i want to combination lists like set1=('a1'), set2=('a2'), set3=('a3'), set4=('a1','a2'), set5=('a1','a3'), set6=('a2','a3'), set7=('a1','a2','a3'). How to access lists set1, set2,... */

Answer 1

If I understand correctly, you want to generate the power set - the set of all subsets of the list. Python's itertools package provides a nice example function to generate this:
from itertools import chain, combinations
def powerset(iterable):
"powerset([1,2,3]) --> () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)"
s = list(iterable)
return chain.from_iterable(combinations(s, r) for r in range(len(s)+1))

Answer 2

While Nathan answers helps with first part of the question, my code will help you making a dictionary, so you can access the sets like sets['set1'] as asked.
from itertools import chain, combinations
def powerset(iterable):
"powerset([1,2,3]) --> () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)"
s = list(iterable)
return chain.from_iterable(combinations(s, r) for r in range(len(s)+1))
def make_dict(comb):
sets = {}
for i, set in enumerate(comb):
sets['set'+str(i)] = set
return sets
if __name__ == '__main__':
sets = make_dict(powerset(['a1','a2','a3','a4']))
print(sets['set1'])
Output
('a1',)