python获取登录cookie

def sign(self):
    url = self.url + "/signin"
    data = {
        "username": self.username,
        "password": self.password,
        "login-submit": "登录"
    }
    session = requests.session()
    response = session.post(url=url, data=data)
    if response.status_code == 200:
        sessionDict = session.cookies.get_dict()