List Python-TypeError：列表索引必须是整数，而不是str

我正在写一个非常非常简单的加密脚本

当我运行它时，发生了一个类型错误：

TypeError:列表索引必须是整数，而不是str'

我查看了一些有关Stackoverflow的问题，但没有任何帮助

我想这是一个非常简单的观点，我在这里错过了

import os

os.system("clear")

content = input("content:" + " ")
filename = input("filename:" + " ")

content = list(content)
file = open(filename, "w")

counter = 0

os.system("clear")

input("Press enter to encrypt...")

for counter in content:
    if content[counter] in "a":
        content[counter] = "z"
    if content[counter] in "b":
        content[counter] = "y"
    if content[counter] in "c":
        content[counter] = "x"
    if content[counter] in "d":
        content[counter] = "w"
    if content[counter] in "e":
        content[counter] = "v"
    if content[counter] in "f":
        content[counter] = "u"
    if content[counter] in "g":
        content[counter] = "t"
    if content[counter] in "h":
        content[counter] = "s"
    if content[counter] in "i":
        content[counter] = "r"
    if content[counter] in "j":
        content[counter] = "q"
    if content[counter] in "k":
        content[counter] = "p"
    if content[counter] in "l":
        content[counter] = "o"
    if content[counter] in "m":
        content[counter] = "n"
    if content[counter] in "n":
        content[counter] = "m"
    if content[counter] in "o":
        content[counter] = "l"
    if content[counter] in "p":
        content[counter] = "k"
    if content[counter] in "q":
        content[counter] = "j"
    if content[counter] in "r":
        content[counter] = "i"
    if content[counter] in "s":
        content[counter] = "h"
    if content[counter] in "t":
        content[counter] = "g"
    if content[counter] in "u":
        content[counter] = "f"
    if content[counter] in "v":
        content[counter] = "e"
    if content[counter] in "w":
        content[counter] = "d"
    if content[counter] in "x":
        content[counter] = "c"
    if content[counter] in "y":
        content[counter] = "b"
    if content[counter] in "z":
        content[counter] = "a"

content = "".join(content)

file.write(content)
file.close()

os.system("clear")

print("Successfully encrypted!")
print("Use 'decrypt.py' to decrypt.")

---

当您开始过多地按Ctrl+V时，请后退一步。。在任何情况下，计数器都是表示正在迭代的字符的字符串，因此内容[counter]因异常消息中给出的原因而无效。换句话说，运行以下命令：for content:printcounter中的计数器，而不是有问题的循环，并添加适当的格式；你看到了什么结果？为什么？使用该观察返回原始问题。如果要迭代序列的索引，请使用。但这并不是真正想要的提示：在Python中字符串是不可变的，这样的单个字符是不能更改的。相反，创建一个不同的变量，比如encryped_content=并在每个循环中向其追加适当的输出。在循环内部，您应该只需要访问计数器，并将其称为其他名称，例如字母，以避免混淆和此加密的内容。