python爬蟲系列(5.3-動態網站的爬取的策略)
一、認識動態網站
所謂的動態網站,是使用ajax加載出來的網頁,我們開啟網頁的時候可以正常顯示內容,但是我們在顯示網頁原始碼的時候,裡面卻找不到該節點.
1、直接分析ajax呼叫的介面,然後通過程式碼請求這個介面
2、採用模擬瀏覽器請求該動態網站,然後獲取網頁資料
一、分析網頁資料請求
from urllib import parse
import requests
def get_html():
"""
定義一個函式獲取拉鉤職位資訊
:return:
"""
params = {
'px': 'default',
'city': '深圳',
'needAddtionalResult': 'false'
}
url = 'https://www.lagou.com/jobs/positionAjax.json?{0}'.format(parse.urlencode(params))
form_data = {
'first': 'true',
'pn': '1',
'kd': 'python',
}
headers = {
'Accept': 'application/json, text/javascript, */*; q=0.01',
'Accept-Encoding': 'gzip, deflate, br',
'Accept-Language': 'zh-CN,zh;q=0.9',
'Connection': 'keep-alive',
'Content-Length': '25',
'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
'Cookie': 'JSESSIONID=ABAAABAAAGFABEFF0428531C82A2DC0C1C0DCAE2CA9FABE; _ga=GA1.2.484492928.1537518656; _gid=GA1.2.808273883.1537518656; _gat=1; Hm_lvt_4233e74dff0ae5bd0a3d81c6ccf756e6=1537518657; user_trace_token=20180921163056-a947353a-bd78-11e8-a518-525400f775ce; LGSID=20180921163056-a9473670-bd78-11e8-a518-525400f775ce; PRE_UTM=; PRE_HOST=; PRE_SITE=; PRE_LAND=https%3A%2F%2Fwww.lagou.com%2F; LGUID=20180921163056-a9473875-bd78-11e8-a518-525400f775ce; TG-TRACK-CODE=index_search; LGRID=20180921163107-af919ae7-bd78-11e8-bb56-5254005c3644; Hm_lpvt_4233e74dff0ae5bd0a3d81c6ccf756e6=1537518667; index_location_city=%E6%B7%B1%E5%9C%B3; SEARCH_ID=a81f58b5627b460b8180ad514b967cf1',
'Host': 'www.lagou.com',
'Origin': 'https://www.lagou.com',
'Referer': 'https://www.lagou.com/jobs/list_python?px=default&city=%E6%B7%B1%E5%9C%B3',
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36',
'X-Anit-Forge-Code': '0',
'X-Anit-Forge-Token': 'None',
'X-Requested-With': 'XMLHttpRequest',
}
response = requests.post(url=url, data=form_data, headers=headers)
print(response.status_code)
print(response.json())
if __name__ == '__main__':
get_html()