def __init__(self, cookies=None):
self._session = requests.Session()<EOL>self._session.headers.update(Default_Header)<EOL>self.proxies = None<EOL>if cookies is not None:<EOL><INDENT>assert isinstance(cookies, str)<EOL>self.login_with_cookies(cookies)<EOL><DEDENT>
创建客户端类实例.

        :param str cookies: 见 :meth:`.login_with_cookies` 中 ``cookies`` 参数
        :return: 知乎客户端对象
        :rtype: ZhihuClient