如何在Python中从字符串中的特定位置（而不是索引）中删除字符

Question

所以我有这个代码：

def myprogram():
import string
import random
import getpass

inputpasswd = getpass.getpass("Password: ")
passwd = ("I<3StackOverflow")
if passwd == inputpasswd:
    qwerty = input("Type something: ")
    def add_str(lst):
        _letters = ("1","2","3","4","5","6","7","8","9","0","q","w","e","r","t","z","u","i","o","p","a","s","d","f","g","h","j","k","l","y","x","c","v","b","n","m","!","#","$","%","&","/","(",")","=","?","*","+","_","-",";"," ")
        return [''.join(random.sample(set(_letters), 1)) + letter + ''.join(random.sample(set(_letters), 1))for letter in lst]

    print(''.join(add_str(qwerty)))
    input("")
else:
    print("Wrong password")
    input("")

我的问题是：我如何制作一个相反的程序，所以它接受了一堆垃圾字母并将其转换为有意义的文本？

示例：如果我在此程序中键入类似“aaaaaaa”的内容，则会将其转换为“mapma＆”at7ar8a2ga-ka *“

在这个新程序中，我想输入“mapma＆”at7ar8a2ga-ka *“并输出”aaaaaaa“。

Answer 1

这对你有用吗？：

s="1a23a45a6"
print(s[1::3]) # aaa

Answer 2

这样做： initial_str = random_str[1:-1:3] ，其中random_str是带垃圾的字符串