百度翻译网页版爬虫

 参考链接：http://www.manongjc.com/article/76959.html

#! /home/python/.virtualenvs/py3_spider/bin/python
"""
2019-8-2
思路:
1.检测输入语言的类型,这个很好实现
2.开始进行翻译,难点:破解表单sign参数
3.破解流程:
a.浏览器全局搜索sign,找出js
b.dug调试,定位加密函数function e(r)
c.在Python中执行js代码,获取sign
d.难点:获取token,gtk,js替换
e.添加为Python脚本,增加可执行权限,可当翻译工具使用
"""

import re

import js2py
import requests


class BaiduFanyi(object):
    """百度中英文翻译"""

    def __init__(self, keywords):
        """
        :param keywords:待检测语言
        """
        self.keywords = keywords
        self.url_root = 'http://fanyi.baidu.com/'  # 翻译根url
        self.url_langdetect = 'https://fanyi.baidu.com/langdetect'  # 检测语言url
        self.url_trans = 'https://fanyi.baidu.com/v2transapi'  # 执行翻译url
        self.headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.81 Safari/537.36',
            'origin': 'https://fanyi.baidu.com',
            'referer': 'https://fanyi.baidu.com/?aldtype=16047'
        }
        self.data_langdetect = {
            'query': self.keywords
        }
        self.session = requests.session()
        self.session.headers = self.headers
        # 创建执行js的环境
        self.context = js2py.EvalJs()

    def langdetect(self):
        """
        发送请求,检测输入的语言类型
        :return: 正常:en:英文,zh:中文;异常:None
        """
        try:
            response = self.session.post(self.url_langdetect, data=self.data_langdetect)
            response_dict = response.json()  # {'error': 0, 'msg': 'success', 'lan': 'zh'}
            if response_dict.get('error') == 0:
                return response_dict.get('lan')
        except Exception as e:
            print(e)

    def get_token_gtk(self):
        """
        获取token,gtk(用于合成sign)
        :return:(token, gtk)
        """
        response = self.session.get(self.url_root)
        response_str = response.content.decode()
        # 注意双引号问题
        token = re.findall(r"token: '(.*?)'", response_str)[0]
        gtk = re.findall(r";window.gtk = ('.*?');", response_str)[0]
        return token, gtk

    def trans(self, lan):
        """
        发送请求,开始翻译
        :return: 正常:翻译结果(str);异常:None
        """
        try:
            token, gtk = self.get_token_gtk()
            # print(token, gtk)  # 2d275a77fc7ba0609e7151f57859040d '320305.131321201'

            js = r"""
            function n(r, o) {
                for (var t = 0; t < o.length - 2; t += 3) {
                var a = o.charAt(t + 2);
                a = a >= "a" ? a.charCodeAt(0) - 87 : Number(a), a = "+" === o.charAt(t + 1) ? r >>> a : r << a, r = "+" === o.charAt(t) ? r + a & 4294967295 : r ^ a
                }
                return r
            }

            function e(r) {
                var o = r.match(/[\uD800-\uDBFF][\uDC00-\uDFFF]/g);
                if (null === o) {
                    var t = r.length;
                    t > 30 && (r = "" + r.substr(0, 10) + r.substr(Math.floor(t / 2) - 5, 10) + r.substr(-10, 10))
                } else {
                    for (var e = r.split(/[\uD800-\uDBFF][\uDC00-\uDFFF]/), C = 0, h = e.length, f = []; h > C; C++) "" !== e[C] && f.push.apply(f, a(e[C].split(""))), C !== h - 1 && f.push(o[C]);
                    var g = f.length;
                    g > 30 && (r = f.slice(0, 10).join("") + f.slice(Math.floor(g / 2) - 5, Math.floor(g / 2) + 5).join("") + f.slice(-10).join(""))
                }
                var u = void 0, l = "" + String.fromCharCode(103) + String.fromCharCode(116) + String.fromCharCode(107);
                u = null !== i ? i : (i = window[l] || "") || "";
                for (var d = u.split("."), m = Number(d[0]) || 0, s = Number(d[1]) || 0, S = [], c = 0, v = 0; v < r.length; v++) {
                    var A = r.charCodeAt(v);
                    128 > A ? S[c++] = A : (2048 > A ? S[c++] = A >> 6 | 192 : (55296 === (64512 & A) && v + 1 < r.length && 56320 === (64512 & r.charCodeAt(v + 1)) ? (A = 65536 + ((1023 & A) << 10) + (1023 & r.charCodeAt(++v)), S[c++] = A >> 18 | 240, S[c++] = A >> 12 & 63 | 128) : S[c++] = A >> 12 | 224, S[c++] = A >> 6 & 63 | 128), S[c++] = 63 & A | 128)
                }
                for (var p = m, F = "" + String.fromCharCode(43) + String.fromCharCode(45) + String.fromCharCode(97) + ("" + String.fromCharCode(94) + String.fromCharCode(43) + String.fromCharCode(54)), D = "" + String.fromCharCode(43) + String.fromCharCode(45) + String.fromCharCode(51) + ("" + String.fromCharCode(94) + String.fromCharCode(43) + String.fromCharCode(98)) + ("" + String.fromCharCode(43) + String.fromCharCode(45) + String.fromCharCode(102)), b = 0; b < S.length; b++) p += S[b], p = n(p, F);
                return p = n(p, D), p ^= s, 0 > p && (p = (2147483647 & p) + 2147483648), p %= 1e6, p.toString() + "." + (p ^ m)
            }
            """
            # js中替换gtk
            js = js.replace(r'null !== i ? i : (i = window[l] || "") || ""', gtk)
            # print(js)

            # 执行js,定义加密函数e(r)
            self.context.execute(js)
            # 执行加密函数e(r),对keywords进行加密
            sign = self.context.e(self.keywords)
            # print(sign)  # 477811.239938

            data = {
                'from': lan,
                'to': 'en' if lan == 'zh' else 'zh',
                'query': self.keywords,
                'transtype': 'translang',
                'simple_means_flag': 3,
                'sign': sign,  # 此参数需破解
                'token': token  # 此参数需破解

            }
            response = self.session.post(self.url_trans, data=data)
            response_dict = response.json()
            ret = response_dict['trans_result']['data'][0]['dst']
            return ret
        except Exception as e:
            print(e)

    def run(self):
        # 1.检测输入的语言类型
        lan = self.langdetect()
        if lan is None:
            return
        # 2.翻译
        ret = self.trans(lan)
        print('%s-->%s' % (self.keywords, ret))  # 中国-->China


def main():
    while True:
        keywords = input('please input the keywords:')
        baidu_fanyi = BaiduFanyi(keywords)
        baidu_fanyi.run()


if __name__ == '__main__':
    main()