python - 尝试加密文本文件会导致TypeError

下面是我的代码：

my_text= F = open("mytext.txt")
KEY=4
encoded= ""

for c in my_text:
    rem = (ord(c) - 97 + KEY) % 26
    encoded += chr(rem + 97)

print(encoded)

错误：

TypeError: ord() expected a character, but string of length 21 found

它返回上面的错误，但我不知道如何解决。

最佳答案

默认情况下，遍历文件会逐行检索数据。您可以使用iter(callable, sentinel)内置函数中的两个参数以字节流的形式读取文件，如下所示。请注意，这种方法不会一次将整个文件读入内存，就像使用内置readlines()之类的操作一样。

KEY = 4
encoded = ""

with open("mytext.txt", 'rb') as my_text:
    # Using iter() like below causes it to quit when read() returns an
    # empty char string (which indicates the end of the file has been
    # reached).
    for c in iter(lambda: my_text.read(1), b''):
        rem = (ord(c) - 97 + KEY) % 26
        encoded += chr(rem + 97)

print(encoded)