python爬虫-----Python访问http的几种方式

爬取页面数据,我们需要访问页面,发送http请求,以下内容就是Python发送请求的几种简单方式:

会使用到的库  urllib   requests

1.urlopen

import urllib.request
import urllib.parse
import urllib.error
import socket
data = bytes(urllib.parse.urlencode({"hello": "world"}),encoding='utf8')
try:
response = urllib.request.urlopen('http://httpbin.org/post',data=data,timeout=10)
print(response.status)
print(response.read().decode('utf-8'))
except urllib.error.URLError as e:
if isinstance(e.reason, socket.timeout):
print("TIMEOUT")

2.requests

用到requests中的get  post  delete  put 方法访问请求  这种比一简单一些

每个方法有相应的参数列表,比如 get  params参数   proxies:设置代理  auth: 认证  timeout :超时时间 等 

import requests
ico = requests.get("https://github.com/favicon.ico")
with open("favicon.ico", "wb") as file:
file.write(ico.content)

3.Request Session

from requests import Session, Request
url = "https://home.cnblogs.com/u/qiutian-guniang/"
s = Session()
req = Request('GET', url=url, headers=header)
pred = s.prepare_request(req)
r = s.send(pred)
print(r.text)
某些网页会禁止抓取数据 我们可以 通过设置User-Agent来设置 使用cookies来保持登录的访问状态例如:以下的cookie内容可以通过在F12控制台获取 复制粘贴 放入headers中

cookies = "_gat=1"

headers = {
"Cookie": cookies,
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; '
'x64) AppleWebKit/537.36 (KHTML, like Gecko) '
'Chrome/68.0.3440.106 Safari/537.36'
}

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转载自www.cnblogs.com/qiutian-guniang/p/11225299.html