BeautifulSoup怎么在Python中使用?很多新手对此不是很清楚,为了帮助大家解决这个难题,下面小编将为大家详细讲解,有这方面需求的人可以来学习下,希望你能有所收获。
python有哪些常用库
python常用的库:1.requesuts;2.scrapy;3.pillow;4.twisted;5.numpy;6.matplotlib;7.pygama;8.ipyhton等。
第一步,访问网址并抓取源码
# -*- coding: utf-8 -*-
import urllib
import urllib2
import re
import os
if __name__ == '__main__':
# 访问网址并抓取源码
url = 'http://www.qiushibaike.com/textnew/page/1/?s=4941357'
user_agent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36'
headers = {'User-Agent':user_agent}
try:
request = urllib2.Request(url = url, headers = headers)
response = urllib2.urlopen(request)
content = response.read()
except urllib2.HTTPError as e:
print e
exit()
except urllib2.URLError as e:
print e
exit()
print content.decode('utf-8')
第二步,利用正则表达式提取信息
首先先观察源码中,你需要的内容的位置以及如何识别
然后用正则表达式去识别读取
注意正则表达式中的 . 是不能匹配\n的,所以需要设置一下匹配模式。
# -*- coding: utf-8 -*-
import urllib
import urllib2
import re
import os
if __name__ == '__main__':
# 访问网址并抓取源码
url = 'http://www.qiushibaike.com/textnew/page/1/?s=4941357'
user_agent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36'
headers = {'User-Agent':user_agent}
try:
request = urllib2.Request(url = url, headers = headers)
response = urllib2.urlopen(request)
content = response.read()
except urllib2.HTTPError as e:
print e
exit()
except urllib2.URLError as e:
print e
exit()
regex = re.compile('<div class="content">.*?<span>(.*?)</span>.*?</div>', re.S)
items = re.findall(regex, content)
# 提取数据
# 注意换行符,设置 . 能够匹配换行符
for item in items:
print item
第三步,修正数据并保存到文件中
# -*- coding: utf-8 -*-
import urllib
import urllib2
import re
import os
if __name__ == '__main__':
# 访问网址并抓取源码
url = 'http://www.qiushibaike.com/textnew/page/1/?s=4941357'
user_agent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36'
headers = {'User-Agent':user_agent}
try:
request = urllib2.Request(url = url, headers = headers)
response = urllib2.urlopen(request)
content = response.read()
except urllib2.HTTPError as e:
print e
exit()
except urllib2.URLError as e:
print e
exit()
regex = re.compile('<div class="content">.*?<span>(.*?)</span>.*?</div>', re.S)
items = re.findall(regex, content)
# 提取数据
# 注意换行符,设置 . 能够匹配换行符
path = './qiubai'
if not os.path.exists(path):
os.makedirs(path)
count = 1
for item in items:
#整理数据,去掉\n,将<br/>换成\n
item = item.replace('\n', '').replace('<br/>', '\n')
filepath = path + '/' + str(count) + '.txt'
f = open(filepath, 'w')
f.write(item)
f.close()
count += 1
第四步,将多个页面下的内容都抓取下来
# -*- coding: utf-8 -*-
import urllib
import urllib2
import re
import os
if __name__ == '__main__':
# 访问网址并抓取源码
path = './qiubai'
if not os.path.exists(path):
os.makedirs(path)
user_agent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36'
headers = {'User-Agent':user_agent}
regex = re.compile('<div class="content">.*?<span>(.*?)</span>.*?</div>', re.S)
count = 1
for cnt in range(1, 35):
print '第' + str(cnt) + '轮'
url = 'http://www.qiushibaike.com/textnew/page/' + str(cnt) + '/?s=4941357'
try:
request = urllib2.Request(url = url, headers = headers)
response = urllib2.urlopen(request)
content = response.read()
except urllib2.HTTPError as e:
print e
exit()
except urllib2.URLError as e:
print e
exit()
# print content
# 提取数据
# 注意换行符,设置 . 能够匹配换行符
items = re.findall(regex, content)
# 保存信息
for item in items:
# print item
#整理数据,去掉\n,将<br/>换成\n
item = item.replace('\n', '').replace('<br/>', '\n')
filepath = path + '/' + str(count) + '.txt'
f = open(filepath, 'w')
f.write(item)
f.close()
count += 1
print '完成'
使用BeautifulSoup对源码进行解析
# -*- coding: utf-8 -*-
import urllib
import urllib2
import re
import os
from bs4 import BeautifulSoup
if __name__ == '__main__':
url = 'http://www.qiushibaike.com/textnew/page/1/?s=4941357'
user_agent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36'
headers = {'User-Agent':user_agent}
request = urllib2.Request(url = url, headers = headers)
response = urllib2.urlopen(request)
# print response.read()
soup_packetpage = BeautifulSoup(response, 'lxml')
items = soup_packetpage.find_all("div", class_="content")
for item in items:
try:
content = item.span.string
except AttributeError as e:
print e
exit()
if content:
print content + "\n"
这是用BeautifulSoup去抓取书本以及其价格的代码
可以通过对比得出到bs4对标签的读取以及标签内容的读取
(因为我自己也没有学到这一部分,目前只能依葫芦画瓢地写)
# -*- coding: utf-8 -*-
import urllib2
import urllib
import re
from bs4 import BeautifulSoup
url = "https://www.packtpub.com/all"
try:
html = urllib2.urlopen(url)
except urllib2.HTTPError as e:
print e
exit()
soup_packtpage = BeautifulSoup(html, 'lxml')
all_book_title = soup_packtpage.find_all("div", class_="book-block-title")
price_regexp = re.compile(u"\s+\$\s\d+\.\d+")
for book_title in all_book_title:
try:
print "Book's name is " + book_title.string.strip()
except AttributeError as e:
print e
exit()
book_price = book_title.find_next(text=price_regexp)
try:
print "Book's price is "+ book_price.strip()
except AttributeError as e:
print e
exit()
print ""
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