How to Build a Python Scraper for Youdao Mobile Translation API

Project Background

Youdao Translate is one of the largest translation apps in China with a huge user base; users often turn to it for quick word or sentence translations.

This article shows how to obtain the mobile translation API used by Youdao.

Project Goal

Enable translation of words or sentences across multiple languages by calling the API.

Libraries and Websites

URL: http://m.youdao.com/translate

Libraries: requests , lxml

Software: PyCharm

Project Analysis

1. Open developer tools (F12), switch to mobile mode, go to the Network panel, and locate the form data under the request headers.

2. The request contains two parameters: inputtext (the word or sentence) and type (the language code).

3. Build a form that sends these two parameters to achieve multi‑language translation.

4. Parse the returned page using XPath to extract translation results.

Implementation

1. Import the required libraries and define a YoudaoSpider class with an initializer.

import requests
from lxml import etree

class YoudaoSpider(object):
    def __init__(self):
        pass

if __name__ == '__main__':
    spider = YoudaoSpider()

Prepare URL and headers

self.trans_url = "http://m.youdao.com/translate"
self.headers = {
    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36"
}

Define get_result method

def get_result(self, word, fro):
    """Construct form data dictionary"""
    data = {
        'inputtext': word,
        'type': fro
    }
    response = requests.post(url=self.trans_url, data=data, headers=self.headers)
    html = response.content.decode('utf-8')
    pa = etree.HTML(html)
    pa_list = pa.xpath("//div[@class='generate']/ul/li/text()")
    for i in pa_list:
        print("翻译为:" + i)

5. Choose the language type and call get_result:

choice = input("1.中翻译英语  2.中翻韩语 3.把中文翻译法语 
请选择1/2/3:
")
if choice == '1':
    fro = 'ZH_CN2EN'
elif choice == '2':
    fro = 'ZH_CN2SP'
elif choice == '3':
    fro = 'ZH_CN2FR'
word = input("请输入你要翻译的单词或句子:")
result = spider.get_result(word, fro)

Result Demonstration

1. Input the translation type.

2. Input the sentence to translate.

Summary

The solution uses a Python web scraper to access Youdao's translation API.

It explains how to construct the request form and parse the response with XPath.

Readers are encouraged to experiment with other languages to deepen their understanding of crawling principles.