百度翻译post爬虫案例

流程图：

1、页面分析：

可以发现post请求，经过试验，query=兄弟、sign='xxx'、token值（token值是固定的，sign数字签名加密，通过百度翻译开发文档寻找发现） 这三个参数最为重要，同时将需要翻译的源语言以及目标语言代码两个参数传入，这里为zh，en

1）首先寻找token值：（通过全局搜索，可以发现token值是固定的）

2）寻找v2transapi资源：首先观察可以发现先是通过langdetect的post请求生成v2transapi的post请求，因此需要关注这个资源下面是否存在sign的加密方法，通过寻找top整个资源找到v2transapi资源所在文件：index_xxx.js

3）寻找sign加密：在index_xxx.js中通过不断打断点寻找sign加密函数，寻找到与类似加密的函数（可以通过不断的断点去尝试），通过断点校验寻找

点击上述js资源链接跳转，通过断点调试可以寻找需要初始定义的i值，i值为固定值，（可能会更新，反爬）：

4）js代码：sign加密所需的函数

function e(r) {var i = '320305.131321201'  ##i值初始化，与u值一致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),  ##需要调用n()函数p ^= s,0 > p && (p = (2147483647 & p) + 2147483648),p %= 1e6,p.toString() + "." + (p ^ m)}##需要调用n()函数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}

5）python执行js代码：利用execjs模块执行

import execjs
def load_js(path):with open(path,'r',encoding='utf-8') as f:jscode = f.read()return jscode
##加载文件
jscode = load_js('./jj.js')
rst = execjs.compile(jscode).call('e','兄弟')
print(rst)

发现sign值加密与页面分析一致，同时经过试验发现，sign加密只与r（这里即需要翻译的源内容有关，与语言类型无关）

6）观察返回结果的页面，可以从json数据中发现，dst：'brother' 即为所需结果

2、代码实现：

import requests
import json
import execjs
class trans(object):#初始化def __init__(self,yuan,target,url,word):self.headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.81 Safari/537.36','Cookie': 'BIDUPSID=B3C094FD6A0FEE417C2703340B4AF2D7; PSTM=1603963404; REALTIME_TRANS_SWITCH=1; FANYI_WORD_SWITCH=1; HISTORY_SWITCH=1; SOUND_SPD_SWITCH=1; SOUND_PREFER_SWITCH=1; BAIDUID=64509CE041C10A411C12FAC982B8D254:FG=1; __yjs_duid=1_c5abf95293c6246880dbd87c0ba25d5d1621231890175; BDORZ=B490B5EBF6F3CD402E515D22BCDA1598; BDSFRCVID=Hx_OJeC62Cz2s3QHjIHqU6pq9mK0ML5TH6aoh4Mt40LUCjQoD1SUEG0P8x8g0Ku-S2-5ogKK3gOTH4DF_2uxOjjg8UtVJeC6EG0Ptf8g0f5; H_BDCLCKID_SF=tb4qVCL5tI-3MDjYb4n_5bJH-UnLqhTZbgOZ0l8KtDI-qJj9jf74MRbW5fLL2-j-QItObn7mWIQHDU5k35OqebIFKl3rX4Qzban4KKJxLbLWeIJo5tKByxP4hUJiB5JMBan7_pbIXKohJh7FM4tW3J0ZyxomtfQxtNRJ0DnjtnLhbC_Cj5K2D6j-eUreaR3-HDrKBRbaHJOoDDvNyUQcy4LdjG5N3hLLfIo7-qc1MP5HKJ7PbtvKbt-V3-Aq54RGJCJD54TP2fbhVJOpXTohQfbQ02cPqP-jW5TahCLEtR7JOpkRbUnxy50vQRPH-Rv92DQMVU52QqcqEIQHQT3m5-5bbN3ht6IDJbKj_KKKfbo5KRopMtOhq4tehH4qbn39WDTOQJ7TtPQs8JcSMx7fbPDe5U7--47-WRvX-pbwBPbcfUnMKn05XM-pXbjMLtnK3mkjbPbOKl3fffAzhnAWQt4syP4eKMRnWnnRKfA-b4ncjRcTehoM3xI8LNj405OTbIFO0KJzJCF5hD09DjKKjjPDbfoJa46MHjn-WJOHat-_Hn7zeTQsyf4pbt-qJtrHbKFf3hn_WUTaHR76M-_BQ5_8bUbnBT5Ka-jMaU5uWII2slO4XKcHb5-kQN3TbhLO5bRiLRoEXbctDn3oyTbJXp0nj-Oly5jtMgOBBJ0yQ4b4OR5JjxonDh83bG7MJPKtfJCeVID2tKP3ejrP-trf5DCShUFsBnvdB2Q-5KL-0-FKqIOhy-6zyb_Ajl3Dq4ritgjr_xbdJJjojKbE5582XhLdMRQy0TogQmTxoUtyMInJhhvGqq-KqjLebPRiJ-b9Qg-JKpQ7tt5W8ncFbT7l5hKpbt-q0x-jLTnhVn0M5DK0HPonHjD2ejv03J; BCLID_BFESS=10263449539173583399; BDSFRCVID_BFESS=Hx_OJeC62Cz2s3QHjIHqU6pq9mK0ML5TH6aoh4Mt40LUCjQoD1SUEG0P8x8g0Ku-S2-5ogKK3gOTH4DF_2uxOjjg8UtVJeC6EG0Ptf8g0f5; H_BDCLCKID_SF_BFESS=tb4qVCL5tI-3MDjYb4n_5bJH-UnLqhTZbgOZ0l8KtDI-qJj9jf74MRbW5fLL2-j-QItObn7mWIQHDU5k35OqebIFKl3rX4Qzban4KKJxLbLWeIJo5tKByxP4hUJiB5JMBan7_pbIXKohJh7FM4tW3J0ZyxomtfQxtNRJ0DnjtnLhbC_Cj5K2D6j-eUreaR3-HDrKBRbaHJOoDDvNyUQcy4LdjG5N3hLLfIo7-qc1MP5HKJ7PbtvKbt-V3-Aq54RGJCJD54TP2fbhVJOpXTohQfbQ02cPqP-jW5TahCLEtR7JOpkRbUnxy50vQRPH-Rv92DQMVU52QqcqEIQHQT3m5-5bbN3ht6IDJbKj_KKKfbo5KRopMtOhq4tehH4qbn39WDTOQJ7TtPQs8JcSMx7fbPDe5U7--47-WRvX-pbwBPbcfUnMKn05XM-pXbjMLtnK3mkjbPbOKl3fffAzhnAWQt4syP4eKMRnWnnRKfA-b4ncjRcTehoM3xI8LNj405OTbIFO0KJzJCF5hD09DjKKjjPDbfoJa46MHjn-WJOHat-_Hn7zeTQsyf4pbt-qJtrHbKFf3hn_WUTaHR76M-_BQ5_8bUbnBT5Ka-jMaU5uWII2slO4XKcHb5-kQN3TbhLO5bRiLRoEXbctDn3oyTbJXp0nj-Oly5jtMgOBBJ0yQ4b4OR5JjxonDh83bG7MJPKtfJCeVID2tKP3ejrP-trf5DCShUFsBnvdB2Q-5KL-0-FKqIOhy-6zyb_Ajl3Dq4ritgjr_xbdJJjojKbE5582XhLdMRQy0TogQmTxoUtyMInJhhvGqq-KqjLebPRiJ-b9Qg-JKpQ7tt5W8ncFbT7l5hKpbt-q0x-jLTnhVn0M5DK0HPonHjD2ejv03J; H_PS_PSSID=34835_34068_31660_34712_34599_34584_34505_34830_34579_34812_26350_34826_34736_34691_34672; delPer=0; ZD_ENTRY=baidu; BAIDUID_BFESS=64509CE041C10A411C12FAC982B8D254:FG=1; PSINO=6; __yjs_st=2_OWNhM2Y3YWUyMjM4Y2YxOWZmNWE4MGE1NzYzZjhiNDkxOGMwN2QzOGFkOGU1MTJiM2E1YjE0MmEzY2QyM2IwNDJiNmI4ODRiNzAwOTk5MDAxMTU3MDYwNWFmNzRkMmU3ODExZmVhOTM0ZTE0NDgxYmQxZGFiOTFjNGY0NGZlNjBiOWQ4YTY1ZjAyMWZlMDlmOTVlMDllM2Y2ZjU4ODM3MjJjMDBjYjk1YjJjYjJhZDJkNjBkZjIxNzE2YTcxNGE5OTQwZDM3OTRiOGFkYWFkMjI5ZTFlZmJhNDFmN2E2NDM4NjMxMzYxMDkwOTQwYTRjNWRkYjFhOTVjYjA3YTljMF83X2Y3YTJlYjY5; ab_sr=1.0.1_MDJjYzhlNWYyZmIwOGNlZDAwOTQwOGExZWZiNGI4OWM4MGFiZDk4N2M2NTlkMTA1OGRiZDdhMzY1NWQ5YzZhN2ZmYzA0Y2ZkN2ViYzcwMmY5NDhjYjQwYjg4ZDcyMmQyODg2NGE0MTE2MmRiZDc1MDRjNzBiNzRiNzJkNzczYWNjYTY2ZDYwY2I1NGIyZmQxMzNjMGFlZTAyOWI2ZjFkYw==; BA_HECTOR=0g010l058ga42180au1gmgtgf0r; Hm_lvt_64ecd82404c51e03dc91cb9e8c025574=1634231163,1634231236,1634233204,1634237535; Hm_lpvt_64ecd82404c51e03dc91cb9e8c025574=1634237535'}##js加密with open('./jj.js', 'r', encoding='utf-8') as f:jscode = f.read()sign = execjs.compile(jscode).call('e', word)self.data = {'from':yuan,'to':target,'query':word,'token':'e74813bab0a8fd9f7fd385e807b79321','sign':sign}self.url = url##post请求def get_data(self):response = requests.post(self.url,headers=self.headers,data=self.data)return response.content##json解析def parse_data(self,data):dict_data = json.loads(data)return dict_data['trans_result']['data'][0]['dst']def run(self):response = self.get_data()fanyi = self.parse_data(response)return fanyi
##通用语言
def tongyong(language):if language in ('汉语','中文','中文简体'):return 'zh'elif language in ('英语','英文'):return 'en'elif language in ('韩语','韩文'):return 'kor'elif language in ('日文','日语'):return 'jp'elif language in ('白话','粤语','广东话'):return 'yue'elif language in ('法语'):return  'fra'else:return False
##输入语言校验
def check(language):j = tongyong(language)if j:return jelse:l = input("请重新输入:")return check(l)if __name__ == '__main__':url = 'https://fanyi.baidu.com/v2transapi'yuan = input("请输入需要翻译语言:")##校验yuan = check(yuan)target = input("请输入目标语言:")##校验target = check(target)word = input('请输入需要翻译内容:')tran = trans(yuan,target,url,word)a = tran.run()print("翻译结果为: "+a)

结果（互动式）