def all_subsequences(ind, a, new_list, fin_list):
    
    if(ind >= len(a)):
        print(new_list)
        fin_list.append(new_list)
        return
    
    new_list.append(a[ind])
    all_subsequences(ind+1, a, new_list, fin_list)
    new_list.pop()
    all_subsequences(ind+1, a, new_list, fin_list)
    
    return fin_list


a = [3,1,2]
new_list = []
final_list = []
result = all_subsequences(0, a, new_list, final_list)
print(result)