Python爬虫学习（二）盗亦有道（三）Requests库网络爬取实战

（二）网络爬虫的盗亦有道

(1)网络爬虫的限制

• 来源审查：检查来访HTTP协议头的User-Agent域

• 发布公告：Robots协议 —— 网站根目录下的robots.txt文件

（三）Requests库网络爬取实战

(1)京东商品页面的爬取

import requests

def getHTMLText(url):
    try:
        Headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36',
        }
        r = requests.get(url,headers=Headers,timeout=30)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        return r.text[:1000]
    except:
        return "产生异常"

if __name__ == "__main__":
    url = "https://item.jd.com/100004323294.html"
    print(getHTMLText(url))

(2)亚马逊商品页面的爬取

import requests

def getHTMLText(url):
    try:
        Headers ={
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36',
            'Cookies': 'session-id=460-2669091-3751610; i18n-prefs=CNY; ubid-acbcn=460-5518508-6686437; x-wl-uid=1ZNig4QusLPyi/2fMRt2+/B9UI77CSP/FURf3oOMMEU5Qkn5d5DWvk3ZFsfCwdw4gQUS8PQ6cQls=; session-token="Tsypc2KcjVgqDHIbYljZ3S6e6UpT8lE0Ep5iBlUEUMOR1c6UOTsT46LMslGbryJIDtKQi9eEPX3DDHl4GrcE39k7YvQKBZkkcJ7Iyz6WJo69+IsEl5RCj4I5lStPd8Aysjq91yFBZT7jviCBycWPKVz+Df2gI+6L5haArRakytUPoYW0t4wASl/nz4LpD8dYh9xlXuBViLQf7en5aVPOhxSU9h7IuM1MDO7wQLYrFiFrICD/rphjTw=="; session-id-time=2082729601l; csm-hit=tb:G7W4MG6KYD3V0Z4C2BPR+s-0AWC79VGM2DFRQZSHM5N|1586669357960&t:1586669357960&adb:adblk_no'
        }
        r = requests.get(url,headers=Headers,timeout=30)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        return r.text
    except:
        return "产生异常"

if __name__ == "__main__":
    url = "https://www.amazon.cn/dp/B07FQKB4TM"
    print(getHTMLText(url))

(3)百度/360搜索关键词提交

• 百度关键词接口：http://www.baidu.com/s?wd=keyword

import requests


def getHTMLSearch(url, keyword):
    try:
        Headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36',
        }
        kv = {'wd': keyword}
        r = requests.get(url, headers=Headers, params=kv, timeout=30)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        return r.text
    except:
        return "产生异常"

    
if __name__ == "__main__":
    url = "http://www.baidu.com/s"
    print(len(getHTMLSearch(url, keyword='Python')))

• 360关键词接口：http://www.so.com/s?q=keyword

import requests


def getHTMLSearch(url, keyword):
    try:
        Headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36',
        }
        kv = {'q': keyword}
        r = requests.get(url, headers=Headers, params=kv, timeout=30)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        return r.text
    except:
        return "产生异常"


if __name__ == "__main__":
    url = "http://www.so.com/s"
    print(len(getHTMLSearch(url, keyword='Python')))

(4)网络图片的爬取和存储

import requests
import os

url = "http://image.nationalgeographic.com.cn/2017/0211/20170211061910157.jpg"
root = "D://pics//"
path = root + url.split('/')[-1]
try:
    if not os.path.exists(root):
        os.mkdir(root)
    if not os.path.exists(path):
        r = requests.get(url)
        with open(path,'wb') as f:
            f.write(r.content)
            f.close()
            print("pic save success")
    else:
        print("pic already exist")
except:
    print("spider fail")

(5)IP地址归属地的自动查询

https://www.ip138.com/iplookup.asp?ip={ipaddress}&action=2

import requests

def getHTMLText(url):
    try:
        Headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36',
        }
        r = requests.get(url,headers=Headers,timeout=30)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        return r.text
    except:
        return "产生异常"

if __name__ == "__main__":
    ip = '202.204.80.112'
    url = "https://www.ip138.com/iplookup.asp?ip={}&action=2".format(ip)
    print(getHTMLText(url))