上课
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)
../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
但是,根据this帖子,rotate
应该是可解析的。请注意,使用类名称VigenereCipher
进行限定也不起作用,因为它找不到VigenereCipher
(这很有意义,因为我们正在定义它)。
我可以将rotate
设为模块级别的方法,并且可以工作,但是我并不想要这样做,因为仅在VigenereCipher
中需要它。
也尝试了this答案,但没有成功。
_TABLE: Final[ClassVar[Dict[str, str]]] = dict({(chr(i + ord("A")), rotate(i)) for i in range(26)})