1 # -*- coding: cp936 -*- 2 pre_n = '010010000100001100000000000000000000000001010001001001001010000101' 3 print '编码过程……………………' 4 length = len(pre_n) 5 pre_list = list(pre_n) 6 for ch in range (0,length): 7     pre_list[ch] = int (pre_list[ch]) 8 store_list = pre_list 9 print pre_list10 ich = -1 ;11 for ch in range (0,length):12     if pre_list[ch] == 1 :13         ich = ich * (-1)14     pre_list[ch] = pre_list[ch]*ich;15 print pre_list16 pre_flag_num = 0;17 flag_zero = 0;18 for ch in range (0,length):19     if pre_list[ch] <> 0 :20         flag_num = pre_list[ch];21         flag_zero = 0;22     else:23         flag_zero += 1;24     if flag_zero == 4 :25         if flag_num == pre_flag_num :26             pre_list[ch-3] = flag_num * -1;27             pre_list[ch] = flag_num * -1;28             pre_flag_num = flag_num * -1;29             for ch_temp in range(ch+1,length):30                 pre_list[ch_temp] = pre_list[ch_temp] * -131         else:32             pre_list[ch] = flag_num ;33         pre_flag_num = pre_list[ch];34         flag_zero = 0;35 print pre_list,'\n 解码过程………………'36 flag_zero = 0;37 for ch in range (0,length):38     if flag_zero == 2 :39         if flag_num == pre_list[ch]:40             flag_zero = 041             for ch_temp in range(ch-3, ch+1):42                 pre_list[ch_temp] = 0;43     if flag_zero == 3 :44         if pre_list[ch] <> 0 :45             flag_zero = 0;46             for ch_temp in range(ch-3, ch+1):47                 pre_list[ch_temp] = 0;48     if pre_list[ch] <> 0 :49         flag_num = pre_list[ch]50         flag_zero = 0;51     else:52         flag_zero += 1;53     pre_list[ch] = abs(pre_list[ch])54 print pre_list55 if pre_list is store_list:56     print "Successed ..."