Python网络爬虫的文件存储问题
我正在使用网络爬虫抓取数据,并把结果(来自某个Twitter页面的推文)存储为每个用户的单独html文件。我打算稍后解析这些html文件,并把数据存入数据库进行分析。不过,我遇到了一个奇怪的问题。
当我运行以下程序——这是整个爬虫的一小部分——我能够为每个关注者生成一个单独的html文件:
import re
import urllib2
import twitter
start_follower = "NYTimesKrugman"
depth = 3
searched = set()
api = twitter.Api()
def crawl(follower, in_depth):
if in_depth > 0:
searched.add(follower)
directory = "C:\\Python28\\Followertest1\\" + follower + ".html"
output = open(directory, 'a')
output.write(follower)
output.write('\n\n')
users = api.GetFriends(follower)
names = set([str(u.screen_name) for u in users])
names -= searched
for name in list(names)[0:5]:
crawl(name, in_depth-1)
crawl(start_follower, depth)
for x in searched:
print x
print "Program is completed."
但是,当我运行完整的爬虫时,却没有为每个关注者生成单独的文件:
import twitter
import urllib
from BeautifulSoup import BeautifulSoup
import re
import time
start_follower = "NYTimeskrugman"
depth = 2
searched = set()
api = twitter.Api()
def add_to_U(user):
U.append(user)
def site(follower): #creates a twitter site url in string format based on the follower username
followersite = "http://mobile.twitter.com/" + follower
return followersite
def getPage(follower): #obtains access to a webapge
url = site(follower)
response = urllib.urlopen(url)
return response
def getSoup(response): #creates the parsing module
html = response.read()
soup = BeautifulSoup(html)
return soup
def gettweets(soup, output):
tags = soup.findAll('div', {'class' : "list-tweet"})#to obtain tweet of a follower
for tag in tags:
a = tag.renderContents()
b = str (a)
output.write(b)
output.write('\n\n')
def are_more_tweets(soup):#to check whether there is more than one page on mobile twitter
links = soup.findAll('a', {'href': True}, {id: 'more_link'})
for link in links:
b = link.renderContents()
test_b = str(b)
if test_b.find('more') != -1:
return True
return False
def getnewlink(soup): #to get the link to go to the next page of tweets on twitter
links = soup.findAll('a', {'href': True}, {id : 'more_link'})
for link in links:
b = link.renderContents()
if str(b) == 'more':
c = link['href']
d = 'http://mobile.twitter.com' +c
return d
def crawl(follower, in_depth): #main method of sorts
if in_depth > 0:
searched.add(follower)
directory = "C:\\Python28\\Followertest2\\" + follower + ".html"
output = open(directory, 'a')
output.write(follower)
output.write('\n\n')
a = getPage(follower)
soup = getSoup(a)
gettweets(soup, output)
tweets = are_more_tweets(soup)
while(tweets):
b = getnewlink(soup)
red = urllib.urlopen(b)
html = red.read()
soup = BeautifulSoup(html)
gettweets(soup, output)
tweets = are_more_tweets(soup)
users = api.GetFriends(follower)
names = set([str(u.screen_name) for u in users])
names -= searched
for name in list(names)[0:5]:
print name
crawl(name, in_depth - 1)
crawl(start_follower, depth)
print("Program done. Look at output file.")
更具体来说,我似乎只为前五个关注者生成了单独的html文件,然后就没有新文件被创建了。希望能得到一些帮助!
1 个回答
1
这里提到的depth
值在代码片段和完整代码中是不一样的(在完整代码中,你只会得到一层递归)。另外,你只从关注者列表中获取前五个名字:for name in list(names)[0:5]:
所以你总共得到六个人:一个是最开始的关注者,还有他们的前五个朋友。