给定以下类
from __future__ import annotations
from typing import ClassVar, Dict, Final
import abc
class Cipher(abc.ABC):
@abc.abstractmethod
def encrypt(self, plaintext: str) -> str:
pass
@abc.abstractmethod
def decrypt(self, ciphertext: str) -> str:
pass
class VigenereCipher(Cipher):
@staticmethod
def rotate(n: int) -> str:
return string.ascii_uppercase[n:] + string.ascii_uppercase[:n]
_TABLE: Final[ClassVar[Dict[str, str]]] = dict({(chr(i + ord("A")), rotate(i)) for i in range(26)})
编译失败 (使用3.8.0版本)
../cipher.py:19: in <module>
class VigenereCipher(Cipher):
../cipher.py:24: in VigenereCipher
_TABLE: Final[ClassVar[Dict[str, str]]] = dict({(chr(i + ord("A")), rotate(i)) for i in range(26)})
../cipher.py:24: in <setcomp>
_TABLE: Final[ClassVar[Dict[str, str]]] = dict({(chr(i + ord("A")), rotate(i)) for i in range(26)})
E NameError: name 'rotate' is not defined
然而,根据这篇帖子所说,rotate
应该是可解析的。需要注意的是,由于我们正在定义它,所以使用类名VigenereCipher
来限定也不起作用,因为它找不到VigenereCipher
(这是有道理的)。
我可以将rotate
设置为模块级别的方法,并且可以工作,但我真的不想这样做,因为它只在VigenereCipher
中需要。
还尝试了这个答案,但没有成功。