requests是python實現的簡單易用的HTTP庫，使用起來比urllib簡潔很多

因為是第三方庫，所以使用前需要cmd安裝

pip install requests

安裝完成後import一下，正常則說明可以開始使用了。

基本用法：

requests.get()用於請求目標網站，型別是一個HTTPresponse型別

import requests
response = requests.get('http://www.baidu.com')
print(response.status_code) # 列印狀態碼
print(response.url) # 列印請求url
print(response.headers) # 列印頭資訊
 
print(response.cookies) # 列印cookie資訊
print(response.text) #以文字形式列印網頁原始碼
print(response.content) #以位元組流形式列印

執行結果：

狀態碼：200

url：www.baidu.com

headers資訊

各種請求方式：

import requests

requests.get('http://httpbin.org/get')
requests.post('http://httpbin.org/post')
requests.put('http://httpbin.org/put')
requests.delete('http://httpbin.org/delete')
requests.head('http://httpbin.org/get')
requests.options('http://httpbin.org/get')

基本的get請求

import requests

response = requests.get('http://httpbin.org/get')
print(response.text)

結果

帶引數的GET請求：

第一種直接將引數放在url內

import requests

response = requests.get(http://httpbin.org/get?name=gemey&age=22)
print(response.text)

結果

另一種先將引數填寫在dict中，發起請求時params引數指定為dict

import requests

data = {
  'name': 'tom','age': 20
}

response = requests.get('http://httpbin.org/get',params=data)
print(response.text)

結果同上

解析json

import requests

response = requests.get('http://httpbin.org/get')
print(response.text)
print(response.json()) #response.json()方法同json.loads(response.text)
print(type(response.json()))

結果

簡單儲存一個二進位制檔案

二進位制內容為response.content

import requests

response = requests.get('http://img.ivsky.com/img/tupian/pre/201708/30/kekeersitao-002.jpg')
b = response.content
with open('F://fengjing.jpg','wb') as f:
  f.write(b)

為你的請求新增頭資訊

import requests
heads = {}
heads['User-Agent'] = 'Mozilla/5.0 ' \
             '(Macintosh; U; Intel Mac OS X 10_6_8; en-us) AppleWebKit/534.50 ' \
             '(KHTML,like Gecko) Version/5.1 Safari/534.50'
 response = requests.get('http://www.baidu.com',headers=headers)

使用代理

同新增headers方法，代理引數也要是一個dict

這裡使用requests庫爬取了IP代理網站的IP與埠和型別

因為是免費的，使用的代理地址很快就失效了。

import requests
import re

def get_html(url):
  proxy = {
    'http': '120.25.253.234:812','https' '163.125.222.244:8123'
  }
  heads = {}
  heads['User-Agent'] = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML,like Gecko) Chrome/49.0.2623.221 Safari/537.36 SE 2.X MetaSr 1.0'
  req = requests.get(url,headers=heads,proxies=proxy)
  html = req.text
  return html

def get_ipport(html):
  regex = r'<td data-title="IP">(.+)</td>'
  iplist = re.findall(regex,html)
  regex2 = '<td data-title="PORT">(.+)</td>'
  portlist = re.findall(regex2,html)
  regex3 = r'<td data-title="型別">(.+)</td>'
  typelist = re.findall(regex3,html)
  sumray = []
  for i in iplist:
    for p in portlist:
      for t in typelist:
        pass
      pass
    a = t+','+i + ':' + p
    sumray.append(a)
  print('高匿代理')
  print(sumray)


if __name__ == '__main__':
  url = 'http://www.kuaidaili.com/free/'
  get_ipport(get_html(url))

結果：

基本POST請求：

import requests

data = {'name':'tom','age':'22'}

response = requests.post('http://httpbin.org/post',data=data)

獲取cookie

#獲取cookie
import requests

response = requests.get('http://www.baidu.com')
print(response.cookies)
print(type(response.cookies))
for k,v in response.cookies.items():
  print(k+':'+v)

結果：

會話維持

import requests

session = requests.Session()
session.get('http://httpbin.org/cookies/set/number/12345')
response = session.get('http://httpbin.org/cookies')
print(response.text)

結果：

證書驗證設定

import requests
from requests.packages import urllib3

urllib3.disable_warnings() #從urllib3中消除警告
response = requests.get('https://www.12306.cn',verify=False) #證書驗證設為FALSE
print(response.status_code)列印結果：200

超時異常捕獲

import requests
from requests.exceptions import ReadTimeout

try:
  res = requests.get('http://httpbin.org',timeout=0.1)
  print(res.status_code)
except ReadTimeout:
  print(timeout)

異常處理

在你不確定會發生什麼錯誤時，儘量使用try...except來捕獲異常

所有的requests exception：

Exceptions

import requests
from requests.exceptions import ReadTimeout,HTTPError,RequestException

try:
  response = requests.get('http://www.baidu.com',timeout=0.5)
  print(response.status_code)
except ReadTimeout:
  print('timeout')
except HTTPError:
  print('httperror')
except RequestException:
  print('reqerror')

25行程式碼帶你爬取4399小遊戲資料

import requests
import parsel
import csv
f = open('4399遊戲.csv',mode='a',encoding='utf-8-sig',newline='')

csv_writer = csv.DictWriter(f,fieldnames=['遊戲地址','遊戲名字'])
csv_writer.writeheader()
for page in range(1,106):
  url = 'http://www.4399.com/flash_fl/5_{}.htm'.format(page)
  headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML,like Gecko) Chrome/81.0.4044.138 Safari/537.36'
  }
  response = requests.get(url=url,headers=headers)
  response.encoding = response.apparent_encoding
  selector = parsel.Selector(response.text)
  lis = selector.css('#classic li')
  for li in lis:
    dit ={}
    data_url = li.css('a::attr(href)').get()
    new_url = 'http://www.4399.com' + data_url.replace('http://','/')
    dit['遊戲地址'] = new_url
    title = li.css('img::attr(alt)').get()
    dit['遊戲名字'] = title
    print(new_url,title)
    csv_writer.writerow(dit)
f.close()

到此這篇關於python爬蟲---requests庫的用法詳解的文章就介紹到這了,更多相關python requests庫內容請搜尋我們以前的文章或繼續瀏覽下面的相關文章希望大家以後多多支援我們！