问如何让python使用更少的内存？

EN

import itertools
from itertools import *
#Bruteforce 0.1
rlist = list()
n1 = 0
n2 = 1
num = int (input("length"))
mainlist = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9','0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'A', 'b', 'B', 'c', 'C', 'd', 'D', 'e', 'F', 'g', 'G', 'h', 'H', 'i', 'I', 'j', 'k', 'K', 'l', 'L', 'm', 'M', 'n', 'N', 'o', 'O','p', 'P','q', 'Q','r', 'R','s', 'S','t', 'T','u','U','v','V','w','W','x','X','y','Y','z','Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'A', 'b', 'B', 'c', 'C', 'd', 'D', 'e', 'F', 'g', 'G', 'h', 'H', 'i', 'I', 'j', 'k', 'K', 'l', 'L', 'm', 'M', 'n', 'N', 'o', 'O','p', 'P','q', 'Q','r', 'R','s', 'S','t', 'T','u','U','v','V','w','W','x','X','y','Y','z','Z']
perm = permutations((mainlist),num)
#Bugs incoming!
for i in list(perm):
    p = ''.join(str(e) for e in i)
    rlist.append(p)
    print(p)
#this is not going to go down the way you think
while True:
    if rlist[n1] == rlist[n2]:
        del rlist[n1]
        n2 = 1
    elif n1 == num ** 124:
        n1+1
        n2 = n1+1
    elif n1 != n2:
        n2+1