作者：落单鸟人 | 来源：互联网 | 2023-09-13 19:33
篇首语：本文由编程笔记#小编为大家整理，主要介绍了Python网络爬虫与信息提取（中国大学mooc）相关的知识，希望对你有一定的参考价值。
目录
- 目录
- Python网络爬虫与信息提取
- 淘宝商品比价定向爬虫
- 目标获取淘宝搜索页面的信息
- 理解淘宝的搜索接口翻页的处理
- 技术路线requests-refootnote
- 代码如下
- 股票数据定向爬虫
Python网络爬虫与信息提取
- 淘宝商品比价定向爬虫
- 股票数据定向爬虫
1. 淘宝商品比价定向爬虫
功能描述
目标：获取淘宝搜索页面的信息
理解：淘宝的搜索接口翻页的处理
代码如下：
#CrowTaobaoPrice.py
import requests
import re
def getHTMLText(url):
try:
r = requests.get(url, timeout=30)
r.raise_for_status()
r.encoding = r.apparent_encoding
return r.text
except:
return ""
def parsePage(ilt, html):
try:
plt = re.findall(r‘\"view_price\"\:\"[\d\.]*\"‘,html)
tlt = re.findall(r‘\"raw_title\"\:\".*?\"‘,html)
for i in range(len(plt)):
price = eval(plt[i].split(‘:‘)[1])
title = eval(tlt[i].split(‘:‘)[1])
ilt.append([price , title])
except:
print("")
def printGoodsList(ilt):
tplt = "{:4}\t{:8}\t{:16}"
print(tplt.format("序号", "价格", "商品名称"))
count = 0
for g in ilt:
count = count + 1
print(tplt.format(count, g[0], g[1]))
def main():
goods = ‘书包‘
depth = 3
start_url = ‘https://s.taobao.com/search?q=‘ + goods
infoList = []
for i in range(depth):
try:
url = start_url + ‘&s=‘ + str(44*i)
html = getHTMLText(url)
parsePage(infoList, html)
except:
continue
printGoodsList(infoList)
main()
流程图：
步骤1：提交商品搜索请求，循环获取页面
步骤2：对于每个页面，提取商品名称和价格信息
步骤3：将信息输出到屏幕上
开始提交商品搜索请求，循环获取页面对于每个页面，提取商品名称和价格信息将信息输出到屏幕上结束
2. 股票数据定向爬虫
1. 列表内容
功能描述
目标：获取上交所和深交所所有股票的名称和交易信息
输出：保存到文件中
技术路线：requests-bs4-re
新浪股票：http://finance.sina.com.cn/stock/
百度股票：https://gupiao.baidu.com/stock/
2.爬取网站原则
选取原则：股票信息静态存在于HTML页面中，非js代码生成，没有Robots协议限制
选取方法：浏览器F12，源代码查看等
选取心态：不要纠结于某个网站，多找信息源尝试
程序结构如下
开始步骤1：从东方财富网获取股票列表步骤2：根据股票列表逐个到百度股票获取个股信息步骤3：将结果存储到文件结束
代码如下
#CrawBaiduStocksA.py
import requests
from bs4 import BeautifulSoup
import traceback
import re
def getHTMLText(url):
try:
r = requests.get(url)
r.raise_for_status()
r.encoding = r.apparent_encoding
return r.text
except:
return ""
def getStockList(lst, stockURL):
html = getHTMLText(stockURL)
soup = BeautifulSoup(html, ‘html.parser‘)
a = soup.find_all(‘a‘)
for i in a:
try:
href = i.attrs[‘href‘]
lst.append(re.findall(r"[s][hz]\d{6}", href)[0])
except:
continue
def getStockInfo(lst, stockURL, fpath):
for stock in lst:
url = stockURL + stock + ".html"
html = getHTMLText(url)
try:
if html=="":
continue
infoDict = {}
soup = BeautifulSoup(html, ‘html.parser‘)
stockInfo = soup.find(‘div‘,attrs={‘class‘:‘stock-bets‘})
name = stockInfo.find_all(attrs={‘class‘:‘bets-name‘})[0]
infoDict.update({‘股票名称‘: name.text.split()[0]})
keyList = stockInfo.find_all(‘dt‘)
valueList = stockInfo.find_all(‘dd‘)
for i in range(len(keyList)):
key = keyList[i].text
val = valueList[i].text
infoDict[key] = val
with open(fpath, ‘a‘, encoding=‘utf-8‘) as f:
f.write( str(infoDict) + ‘\n‘ )
except:
traceback.print_exc()
continue
def main():
stock_list_url = ‘http://quote.eastmoney.com/stocklist.html‘
stock_info_url = ‘https://gupiao.baidu.com/stock/‘
output_file = ‘D:/BaiduStockInfo.txt‘
slist=[]
getStockList(slist, stock_list_url)
getStockInfo(slist, stock_info_url, output_file)
main()
代码优化
1.编码识别优化
2.增加动态进度显示
优化后代码如下
import requests
from bs4 import BeautifulSoup
import traceback
import re
def getHTMLText(url, code="utf-8"):
try:
r = requests.get(url)
r.raise_for_status()
r.encoding = code
return r.text
except:
return ""
def getStockList(lst, stockURL):
html = getHTMLText(stockURL, "GB2312")
soup = BeautifulSoup(html, ‘html.parser‘)
a = soup.find_all(‘a‘)
for i in a:
try:
href = i.attrs[‘href‘]
lst.append(re.findall(r"[s][hz]\d{6}", href)[0])
except:
continue
def getStockInfo(lst, stockURL, fpath):
count = 0
for stock in lst:
url = stockURL + stock + ".html"
html = getHTMLText(url)
try:
if html=="":
continue
infoDict = {}
soup = BeautifulSoup(html, ‘html.parser‘)
stockInfo = soup.find(‘div‘,attrs={‘class‘:‘stock-bets‘})
name = stockInfo.find_all(attrs={‘class‘:‘bets-name‘})[0]
infoDict.update({‘股票名称‘: name.text.split()[0]})
keyList = stockInfo.find_all(‘dt‘)
valueList = stockInfo.find_all(‘dd‘)
for i in range(len(keyList)):
key = keyList[i].text
val = valueList[i].text
infoDict[key] = val
with open(fpath, ‘a‘, encoding=‘utf-8‘) as f:
f.write( str(infoDict) + ‘\n‘ )
count = count + 1
print("\r当前进度: {:.2f}%".format(count*100/len(lst)),end="")
except:
count = count + 1
print("\r当前进度: {:.2f}%".format(count*100/len(lst)),end="")
continue
def main():
stock_list_url = ‘http://quote.eastmoney.com/stocklist.html‘
stock_info_url = ‘https://gupiao.baidu.com/stock/‘
output_file = ‘D:/BaiduStockInfo.txt‘
slist=[]
getStockList(slist, stock_list_url)
getStockInfo(slist, stock_info_url, output_file)
main()
来自
Python网络爬虫与信息提取
中国大学mooc
http://www.icourse163.org/learn/BIT-1001870001?tid=1001962001#/learn/content?type=detail&id=1002699548&cid=1003101008
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