时间:2020-11-05 python爬虫 查看: 984
获取首页元素信息:
目标 test_URL:http://www.xxx.com.cn/
首先检查元素,a 标签下是我们需要爬取得链接,通过获取链接路径,定位出我们需要的信息
soup = Bs4(reaponse.text, "lxml")
urls_li = soup.select("#mainmenu_top > div > div > ul > li")
首页的URL链接获取:
完成首页的URL链接获取,具体代码如下:
'''
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'''
def get_first_url():
list_href = []
reaponse = requests.get("http://www.xxx.com.cn", headers=headers)
soup = Bs4(reaponse.text, "lxml")
urls_li = soup.select("#mainmenu_top > div > div > ul > li")
for url_li in urls_li:
urls = url_li.select("a")
for url in urls:
url_href = url.get("href")
list_href.append(head_url+url_href)
out_url = list(set(list_href))
for reg in out_url:
print(reg)
遍历第一次返回的结果:
从第二步获取URL的基础上,遍历请求每个页面,获取页面中的URL链接,过滤掉不需要的信息
具体代码如下:
def get_next_url(urllist):
url_list = []
for url in urllist:
response = requests.get(url,headers=headers)
soup = Bs4(response.text,"lxml")
urls = soup.find_all("a")
if urls:
for url2 in urls:
url2_1 = url2.get("href")
if url2_1:
if url2_1[0] == "/":
url2_1 = head_url + url2_1
url_list.append(url2_1)
if url2_1[0:24] == "http://www.xxx.com.cn":
url2_1 = url2_1
url_list.append(url2_1)
else:
pass
else:
pass
else:
pass
else:
pass
url_list2 = set(url_list)
for url_ in url_list2:
res = requests.get(url_)
if res.status_code ==200:
print(url_)
print(len(url_list2))
递归循环遍历:
递归实现爬取所有url,在get_next_url()函数中调用自身,代码如下:
get_next_url(url_list2)
全部代码如下:
import requests
from bs4 import BeautifulSoup as Bs4
head_url = "http://www.xxx.com.cn"
headers = {
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 Safari/537.36"
}
def get_first_url():
list_href = []
reaponse = requests.get(head_url, headers=headers)
soup = Bs4(reaponse.text, "lxml")
urls_li = soup.select("#mainmenu_top > div > div > ul > li")
for url_li in urls_li:
urls = url_li.select("a")
for url in urls:
url_href = url.get("href")
list_href.append(head_url+url_href)
out_url = list(set(list_href))
return out_url
def get_next_url(urllist):
url_list = []
for url in urllist:
response = requests.get(url,headers=headers)
soup = Bs4(response.text,"lxml")
urls = soup.find_all("a")
if urls:
for url2 in urls:
url2_1 = url2.get("href")
if url2_1:
if url2_1[0] == "/":
url2_1 = head_url + url2_1
url_list.append(url2_1)
if url2_1[0:24] == "http://www.xxx.com.cn":
url2_1 = url2_1
url_list.append(url2_1)
else:
pass
else:
pass
else:
pass
else:
pass
url_list2 = set(url_list)
for url_ in url_list2:
res = requests.get(url_)
if res.status_code ==200:
print(url_)
print(len(url_list2))
get_next_url(url_list2)
if __name__ == "__main__":
urllist = get_first_url()
get_next_url(urllist)
以上这篇Python3 实现爬取网站下所有URL方式就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持python博客。