爬虫——控制台抓包和requests.post()发送请求

控制台抓包

打开方式及常用选项

1、打开浏览器，F12打开控制台，找到Network选项卡

2、控制台常用选项

1、Network: 抓取网络数据包

1、ALL: 抓取所有的网络数据包

2、XHR：抓取异步加载的网络数据包

3、JS : 抓取所有的JS文件

2、Sources: 格式化输出并打断点调试JavaScript代码，助于分析爬虫中一些参数

3、Console: 交互模式，可对JavaScript中的代码进行测试

3、抓取具体网络数据包后

1、单击左侧网络数据包地址，进入数据包详情，查看右侧

2、右侧:

1、Headers: 整个请求信息 General、Response Headers、Request Headers、Query String、Form Data

2、Preview: 对响应内容进行预览

3、Response：响应内容

requests.post()

适用于Post类型请求的网站，比例：网易翻译

参数-data

response = requests.post(url,data=data,headers=headers)

# data ：post的数据(Form表单数据，字典格式)

请求方式的特点

GET请求 : 参数在URL地址中有显示

POST请求: Form表单提交数据

有道翻译破解案例(post)

1、目标

破解有道翻译接口，抓取翻译结果# 结果展示请输入要翻译的词语: elephant翻译结果: 大象**************************请输入要翻译的词语: 喵喵叫翻译结果: mews

2、实现步骤

1. 浏览器F12开启网络抓包,Network-All,页面翻译单词后找Form表单数据
2. 在页面中多翻译几个单词，观察Form表单数据变化(有数据是加密字符串)
3. 刷新有道翻译页面，抓取并分析JS代码(本地JS加密)
4. 找到JS加密算法，用Python按同样方式加密生成加密数据
5. 将Form表单数据处理为字典，通过requests.post()的data参数发送

具体实现

1、开启F12抓包，找到Form表单数据如下:

i: 喵喵叫from: AUTOto: AUTOsmartresult: dictclient: fanyideskwebsalt: 15614112641250sign: 94008208919faa19bd531acde36aac5dts: 1561411264125bv: f4d62a2579ebb44874d7ef93ba47e822doctype: jsonversion: 2.1keyfrom: fanyi.webaction: FY_BY_REALTlME

2、在页面中多翻译几个单词，观察Form表单数据变化，我们发现每次查询单词，只有salt、sign和ts的值会变化。其他的值都不会改变。

salt: 15614112641250sign: 94008208919faa19bd531acde36aac5dts: 1561411264125

3、salt、sign和ts的值一般为本地js文件加密，刷新页面，找到js文件并分析JS代码

方法1：Network - JS选项 - 打开一个js文件，左下角格式化符号{}，ctrl+F搜索关键词salt，如果存在关键词则找到了加密的js文件。方法2：控制台右上角 - Search - 搜索salt - 跳转到Sources，查看文件 - 把js文件代码复制到在线js格式化网站，格式化代码，变成有缩进的可读代码。

4、打开JS文件，分析js加密算法，用Python实现

# ts : 经过分析为13位的时间戳，字符串类型

js代码实现: r = "" + (new Date).getTime()

python实现: str(int(time.time()*1000))

# saltjs代码实现: r + parseInt(10 * Math.random(), 10);

python实现: ts + str(random.randint(0,9))

# sign(设置断点调试，来查看 e 的值，发现 e 为要翻译的单词)

js代码实现: n.md5("fanyideskweb" + e + salt + "n%A-rKaT5fb[Gy?;N5@Tj")

python实现:

from hashlib import md5

s = md5()

s.update("fanyideskweb" + e + salt + "n%A-rKaT5fb[Gy?;N5@Tj".encode())

sign = s.hexdigest()

python中正则处理header和formdata

1、pycharm进入方法 ：Ctrl + r ，选中 Regex

2、处理headers和formdata

(.*): (.*)

"$1": "$2",

3、点击 Replace All

5、代码实现

import requests
import time
import random
from hashlib import md5


class YdSpider(object):
    def __init__(self):
        # url一定为F12抓到的 headers -> General -> Request URL
        self.url = 'http://fanyi.youdao.com/translate_o?smartresult=dict&smartresult=rule'
        self.headers = {
            # 检查项最高 - 3个
            "Cookie": "[email protected]; OUTFOX_SEARCH_USER_ID_NCOO=570559528.1224236; _nt\
            es_nnid=96bc13a2f5ce64962adfd6a278467214,1551873108952; JSESSIONID=aaae9i7plXPlKaJH_gkYw; td_cookie=1844\
            6744072941336803; SESSION_FROM_COOKIE=unknown; ___rl__test__cookies=1565689460872",
            "Referer": "http://fanyi.youdao.com/",
            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.\
            0.3809.100 Safari/537.36", }

    # 获取,ts、salt、sign
    def get_salt_sign_ts(self, word):
        ts = str(int(time.time() * 1000))  # ts
        salt = ts + str(random.randint(0, 9))  # salt
        string = "fanyideskweb" + word + salt + "n%A-rKaT5fb[Gy?;N5@Tj"  # sign
        s = md5()
        s.update(string.encode('utf-8'))
        sign = s.hexdigest()

        return salt, sign, ts

    def attack_yd(self, word):
        # 1. 先拿到salt,sign,ts
        salt, sign, ts = self.get_salt_sign_ts(word)
        # 2. 定义form表单数据为字典: data={}
        # 检查了salt sign
        data = {
            "i": word,
            "from": "AUTO",
            "to": "AUTO",
            "smartresult": "dict",
            "client": "fanyideskweb",
            "salt": salt,
            "sign": sign,
            "ts": ts,
            "bv": "7e3150ecbdf9de52dc355751b074cf60",
            "doctype": "json",
            "version": "2.1",
            "keyfrom": "fanyi.web",
            "action": "FY_BY_REALTlME",
        }
        # 3. 直接发请求:requests.post(url,data=data,headers=xxx)
        res = requests.post(url=self.url, data=data, headers=self.headers)
        # res.json() 将json格式的字符串转为python数据类型
        html = res.json()
        result = html['translateResult'][0][0]['tgt']
        print(result)
        # html:{'translateResult': [[{'tgt': '你好', 'src': 'hello'}]], 'errorCode': 0, 'type': 'en2zh-CHS',
        # 'smartResult': {'entries': ['', 'n. 表示问候， 惊奇或唤起注意时的用语\r\n', 'int. 喂；哈罗\r\n', 'n.
        # (Hello)人名；(法)埃洛\r\n'], 'type': 1}}

    def main(self):
        word = input('请输入要翻译的单词:')  # 输入翻译单词
        self.attack_yd(word)


if __name__ == '__main__':
    spider = YdSpider()
    spider.main()

百度翻译破解案例(post)

破解百度翻译接口，抓取翻译结果数据

实现步骤

1、F12抓包，先翻译几个单词，查看异步数据包，找到翻译结果的json的地址，观察查询参数

1、POST地址: https://fanyi.baidu.com/v2transapi2、Form表单数据(多次抓取在变的字段)   from: zh   to: en   sign: 54706.276099  #这个是如何生成的？   token: a927248ae7146c842bb4a94457ca35ee # 基本固定,但也想办法获取

2、抓取相关JS文件

　　右上角 - 搜索 - sign: - 找到具体JS文件(index_c8a141d.js) - 格式化输出

3、在JS中寻找sign的生成代码

1、在格式化输出的JS代码中搜索: sign: 找到如下JS代码：sign: m(a),2、通过设置断点，找到m(a)函数的位置，即生成sign的具体函数   1. a 为要翻译的单词   2. 鼠标移动到 m(a) 位置处，点击上方可进入具体m(a)函数代码块

4、生成sign的m(a)函数具体代码如下(在一个大的define中)，我们复制了里面的3个函数在下面

function a(r) {
        if (Array.isArray(r)) {
            for (var o = 0, t = Array(r.length); o < r.length; o++)
                t[o] = r[o];
            return t
        }
        return Array.from(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] || "") || "";
 //    String.fromCharCode(103)="g"
 //    String.fromCharCode(103)="t"
 //    String.fromCharCode(103)="k"
 //    window.gtk也就是从网页源码中取值
 //    进入函数断点调试
    var u = '320305.131321201'

    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)
}

5、因为js代码太复杂，我们很难用js复现算法，因此我们采用第二种方案，直接将这段代码写入本地js文件，利用pyexecjs模块执行js代码进行调试

import execjs

with open('translate.js', 'r') as f:
    js_data = f.read()

# 创建对象
js_obj = execjs.compile(js_data)
sign = js_obj.eval('e("monkey")')  # 把monkey调入e函数

print(sign)     # 546500.833013

6、获取token

　　在js中 token=window.common.token，在响应(响应即网页源码)中想办法获取此值，百度翻译的网页地址为token_url = 'https://fanyi.baidu.com/?aldtype=16047'。用正则去匹配 regex: "token: '(.*?)'"

代码实现

import requests
import re
import execjs


class BaiduTranslateSpider(object):
    def __init__(self):
        self.token_url = 'https://fanyi.baidu.com/?aldtype=16047'
        self.post_url = 'https://fanyi.baidu.com/v2transapi'
        self.headers = {
            'accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3',
            # 'accept-encoding': 'gzip, deflate, br',
            'accept-language': 'zh-CN,zh;q=0.9',
            'cache-control': 'no-cache',
            'cookie': 'BAIDUID=52920E829C1F64EE98183B703F4E37A9:FG=1; BIDUPSID=52920E829C1F64EE98183B703F4E37A9; PSTM=1562657403; to_lang_often=%5B%7B%22value%22%3A%22en%22%2C%22text%22%3A%22%u82F1%u8BED%22%7D%2C%7B%22value%22%3A%22zh%22%2C%22text%22%3A%22%u4E2D%u6587%22%7D%5D; REALTIME_TRANS_SWITCH=1; FANYI_WORD_SWITCH=1; HISTORY_SWITCH=1; SOUND_SPD_SWITCH=1; SOUND_PREFER_SWITCH=1; delPer=0; BDORZ=B490B5EBF6F3CD402E515D22BCDA1598; BCLID=6890774803653935935; BDSFRCVID=4XAsJeCCxG3DLCbwbJrKDGwjNA0UN_I3KhXZ3J; H_BDCLCKID_SF=tRk8oIDaJCvSe6r1MtQ_M4F_qxby26nUQ5neaJ5n0-nnhnL4W46bqJKFLtozKMoI3C7fotJJ5nololIRy6CKjjb-jaDqJ5n3bTnjstcS2RREHJrg-trSMDCShGRGWlO9WDTm_D_KfxnkOnc6qJj0-jjXqqo8K5Ljaa5n-pPKKRAaqD04bPbZL4DdMa7HLtAO3mkjbnczfn02OP5P5lJ_e-4syPRG2xRnWIvrKfA-b4ncjRcTehoM3xI8LNj405OTt2LEoDPMJKIbMI_rMbbfhKC3hqJfaI62aKDs_RCMBhcqEIL4eJOIb6_w5gcq0T_HttjtXR0atn7ZSMbSj4Qo5pK95p38bxnDK2rQLb5zah5nhMJS3j7JDMP0-4rJhxby523i5J6vQpnJ8hQ3DRoWXPIqbN7P-p5Z5mAqKl0MLIOkbC_6j5DWDTvLeU7J-n8XbI60XRj85-ohHJrFMtQ_q4tehHRMBUo9WDTm_DoTttt5fUj6qJj855jXqqo8KMtHJaFf-pPKKRAashnzWjrkqqOQ5pj-WnQr3mkjbn5yfn02OpjPX6joht4syPRG2xRnWIvrKfA-b4ncjRcTehoM3xI8LNj405OTt2LEoC0XtIDhMDvPMCTSMt_HMxrKetJyaR0JhpjbWJ5TEPnjDUOdLPDW-46HBM3xbKQw5CJGBf7zhpvdWhC5y6ISKx-_J68Dtf5; ZD_ENTRY=baidu; PSINO=2; H_PS_PSSID=26525_1444_21095_29578_29521_28518_29098_29568_28830_29221_26350_29459; locale=zh; Hm_lvt_64ecd82404c51e03dc91cb9e8c025574=1563426293,1563996067; from_lang_often=%5B%7B%22value%22%3A%22zh%22%2C%22text%22%3A%22%u4E2D%u6587%22%7D%2C%7B%22value%22%3A%22en%22%2C%22text%22%3A%22%u82F1%u8BED%22%7D%5D; Hm_lpvt_64ecd82404c51e03dc91cb9e8c025574=1563999768; yjs_js_security_passport=2706b5b03983b8fa12fe756b8e4a08b98fb43022_1563999769_js',
            'pragma': 'no-cache',
            'upgrade-insecure-requests': '1',
            'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36',}

    # 获取token和gtk
    def get_token(self):
        # 定义请求头
        r = requests.get(self.token_url, headers=self.headers)
        token = re.findall(r"token: '(.*?)'", r.text)
        window_gtk = re.findall(r"window.*?gtk = '(.*?)';", r.text)
        if token:
            return token[0], window_gtk[0]

    # 获取sign
    def get_sign(self, word, gtk):
        with open('translate.js', 'r') as f:
            js_data = f.read()

        exec_object = execjs.compile(js_data)
        sign = exec_object.eval('e("{}","{}")'.format(word, gtk))

        return sign

    # 主函数
    def main(self, word, fro, to):
        token, gtk = self.get_token()
        sign = self.get_sign(word, gtk)
        # 找到form表单数据如下,sign和token需要想办法获取
        form_data = {
            'from': fro,
            'to': to,
            'query': word,
            'transtype': 'realtime',
            'simple_means_flag': '3',
            'sign': sign,
            'token': token
        }
        r = requests.post(self.post_url, data=form_data, headers=self.headers)
        print(r.json()['trans_result']['data'][0]['dst'])


if __name__ == '__main__':
    spider = BaiduTranslateSpider()
    choice = input('1. 英译汉 2. 汉译英 : ')
    word = input('请输入要翻译的单词:')
    if choice == '1':
        fro, to = 'en', 'zh'
    elif choice == '2':
        fro, to = 'zh', 'en'

    spider.main(word, fro, to)