Question

我是一名程序员，对于python来说还是一个新手，我无法理解为什么在这段代码中使用类方法

class Mnemonic(object):
    def __init__(self, language):
        self.radix = 2048

    @classmethod
    def _get_directory(cls):
        return os.path.join(os.path.dirname(__file__), 'wordlist')

    @classmethod
    def list_languages(cls):
        return [f.split('.')[0] for f in os.listdir(cls._get_directory()) if f.endswith('.txt')]

    @classmethod
    def normalize_string(cls, txt):
        if isinstance(txt, str if sys.version < '3' else bytes):
            utxt = txt.decode('utf8')
        elif isinstance(txt, unicode if sys.version < '3' else str):
            utxt = txt
        else:
            raise TypeError("String value expected")

        return unicodedata.normalize('NFKD', utxt)

    @classmethod
    def detect_language(cls, code):
        code = cls.normalize_string(code)
        first = code.split(' ')[0]
        languages = cls.list_languages()

        for lang in languages:
            mnemo = cls(lang)
            if first in mnemo.wordlist:
                return lang

        raise ConfigurationError("Language not detected")

    def generate(self, strength=128):
        # Do Stuff

    def to_entropy(self, words):
        # Do Stuff

    def to_mnemonic(self, data):
        # Do Stuff

    def check(self, mnemonic):
        # Do Stuff

    def expand_word(self, prefix):
        # Do Stuff

    def expand(self, mnemonic):
                # Do Stuff

    @classmethod
    def to_seed(cls, mnemonic, passphrase=''):
        mnemonic = cls.normalize_string(mnemonic)
        passphrase = cls.normalize_string(passphrase)
        return PBKDF2(mnemonic, u'mnemonic' + passphrase, iterations=PBKDF2_ROUNDS, macmodule=hmac, digestmodule=hashlib.sha512).read(64)

助记符在任何地方都没有被用作父类，我可以看到它在detect_language()中被使用的原因，但我不明白为什么它被用在_get_directory()上

Answer 1

您的关注是有效的，这不是编写python类方法的最佳实践。这里不需要@classmethod参数，例如，_get_directory()方法也可能是它自己的函数，因为它没有与类的连接。在java中，一切都必须是类或类，所以这看起来像是java dev中的python代码。

了解类方法的用法

1 个答案: