参考 https://github.com/zkqiang/Zhihu-Login

# -*- coding: utf-8 -*-

import scrapy

import time

import re

import base64

import hmac

import hashlib

import json

import matplotlib.pyplot as plt

from PIL import Image

class ZhihuSpider(scrapy.Spider):

    name = 'zhihu'

    allowed_domains = ['www.zhihu.com']

    start_urls = ['http://www.zhihu.com/']

    login_url = 'https://www.zhihu.com/signup'

    login_api = 'https://www.zhihu.com/api/v3/oauth/sign_in'

    login_data = {

        'client_id': 'c3cef7c66a1843f8b3a9e6a1e3160e20',

        'grant_type': 'password',

        'source': 'com.zhihu.web',

        'username': "+86xxxxxx",

        'password': "xxxxxx",

        # 传入'cn'是倒立汉字验证码

        'lang': 'en',

        'ref_source': 'homepage'

    }

    headers = {

        'Connection': 'keep-alive',

        'Host': 'www.zhihu.com',

        'Referer': 'https://www.zhihu.com/',

        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) '

                        'AppleWebKit/537.36 (KHTML, like Gecko) '

                        'Chrome/69.0.3497.100 Safari/537.36'

    }

    def start_requests(self):

        if self.login_data["lang"] == 'cn':

            api = 'https://www.zhihu.com/api/v3/oauth/captcha?lang=cn'

        else:

            api = 'https://www.zhihu.com/api/v3/oauth/captcha?lang=en'

        yield scrapy.Request(url=api, headers=self.headers, callback=self._is_need_captcha)

    def _is_need_captcha(self, response):

        show_captcha = re.search(r'true', response.text)

        if show_captcha:

            yield scrapy.Request(url=response.url,

                                 headers=self.headers,

                                 method="PUT",

                                 callback=self._get_captcha)

        else:

            timestamp = str(int(time.time() * 1000))

            self.login_data.update({

                'captcha': "",

                'timestamp': timestamp,

                'signature': self._get_signature(timestamp)

            })

            yield scrapy.FormRequest(

                url=self.login_api,

                formdata=self.login_data,

                headers=self.headers,

                callback=self.check_login

            )

    def _get_captcha(self, response):

        json_data = json.loads(response.text)

        img_base64 = json_data['img_base64'].replace(r'\n', '')

        with open('./captcha.jpg', 'wb') as f:

            f.write(base64.b64decode(img_base64))

        img = Image.open('./captcha.jpg')

        if self.login_data["lang"] == 'cn':

            plt.imshow(img)

            print('点击所有倒立的汉字，按回车提交')

            points = plt.ginput(7)

            capt = json.dumps({'img_size': [200, 44],

                               'input_points': [[i[0] / 2, i[1] / 2] for i in points]})

        else:

            img.show()

            capt = input('请输入图片里的验证码：')

        # 这里必须先把参数 POST 验证码接口

        yield scrapy.FormRequest(url=response.url,

                           formdata={'input_text': capt},

                           headers=self.headers,

                           callback=self.captcha_login,

                           meta={"captcha":capt}

                           )

    def captcha_login(self, response):

        timestamp = str(int(time.time() * 1000))

        self.login_data.update({

            'captcha': response.meta['captcha'],

            'timestamp': timestamp,

            'signature': self._get_signature(timestamp)

        })

        yield scrapy.FormRequest(

            url=self.login_api,

            formdata=self.login_data,

            headers=self.headers,

            callback=self.check_login

        )

    def check_login(self, response):

        yield scrapy.Request(

            url=self.login_url,

            headers=self.headers,

            callback=self.parse

        )

    def _get_signature(self, timestamp):

        """

        通过 Hmac 算法计算返回签名

        实际是几个固定字符串加时间戳

        :param timestamp: 时间戳

        :return: 签名

        """

        ha = hmac.new(b'd1b964811afb40118a12068ff74a12f4', digestmod=hashlib.sha1)

        grant_type = self.login_data['grant_type']

        client_id = self.login_data['client_id']

        source = self.login_data['source']

        ha.update(bytes((grant_type + client_id + source + timestamp), 'utf-8'))

        return ha.hexdigest()

    def parse(self, response):

        print(response.text)