【Python爬虫笔记】有道翻译POST请求获取结果

使用Python来对有道翻译的结果进行获取，首先进入有道在线翻译首页，F12进入开发者模式。随便翻译一个词语，找到Form Data的部分，这便是我们翻译时提交的数据。

将内容复制后，并且封装为字典（其中key为想要翻译的关键词）：

formdata = {
    "i": key,
    "from": "AUTO",
    "to": "AUTO",
    "smartresult": "dict",
    "client": "fanyideskweb",
    "salt": "15940419133889",
    "sign": "b736c8dcc0a8eb18b0e31492de31cdd5",
    "ts": "1594041913388",
    "bv": "02a6ad4308a3443b3732d855273259bf",
    "doctype": "json",
    "version": "2.1",
    "keyfrom": "fanyi.web",
    "action": "FY_BY_CLICKBUTTION"
}

然后封装成数据包：

data = urllib.parse.urlencode(formdata).encode(encoding='utf-8')

发起POST请求：

#自定义请求，需要把data也传进去
req = request.Request(url, data=data, headers=headers)

#返回请求结果
resp = request.urlopen(req).read().decode()

输出resp，观察结果发现"tgt"的值为翻译的结果：

Please enter waht you want to translate:你好
{"type":"ZH_CN2EN","errorCode":0,"elapsedTime":1,
 		 "translateResult":[[{"src":"你好","tgt":"hello"}]]}

通过正则表达式获取"tgt"的值：

pat = r'"tgt":"(.*?)"}]]'

使用re.findall()来筛选返回结果resp中符合pat的内容，即为翻译的结果：

Please enter waht you want to translate:hello
你好

完整代码如下：

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

import urllib
from urllib import request
import re

headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36"}

url = "http://fanyi.youdao.com/translate?smartresult=dict&smartresult=rule"

key = input("Please enter waht you want to translate:")

#POST需要提交的数据
formdata = {
    "i": key,
    "from": "AUTO",
    "to": "AUTO",
    "smartresult": "dict",
    "client": "fanyideskweb",
    "salt": "15940419133889",
    "sign": "b736c8dcc0a8eb18b0e31492de31cdd5",
    "ts": "1594041913388",
    "bv": "02a6ad4308a3443b3732d855273259bf",
    "doctype": "json",
    "version": "2.1",
    "keyfrom": "fanyi.web",
    "action": "FY_BY_CLICKBUTTION"
}

data = urllib.parse.urlencode(formdata).encode(encoding='utf-8')

#自定义请求，需要把data也传进去
req = request.Request(url, data=data, headers=headers)

#返回请求结果
resp = request.urlopen(req).read().decode()

#正则表达式，提取'"tgt":"和"}]]'中间的任意内容
pat = r'"tgt":"(.*?)"}]]'
#使用re，查找返回的resp中符合pat的内容，即翻译的结果
result = re.findall(pat, resp)

print(result[0])