Question

Below is a small snippet of code I have for my twitter crawler mechanism:

from BeautifulSoup import BeautifulSoup
import re
import urllib2

url = 'http://mobile.twitter.com/NYTimesKrugman'

def gettweets(soup):
    tags = soup.findAll('div', {'class' : "list-tweet"})#to obtain tweet of a follower
    for tag in tags: 
        print tag.renderContents()
        print ('\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'):
            return True
        else:
            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 checkforstamp(soup): # the parser scans a webpage to check if any of the tweets are older than 3 months
    times = soup.findAll('a', {'href': True}, {'class': 'status_link'})
    for time in times:
        stamp = time.renderContents()
        test_stamp = str(stamp)
        if test_stamp == '3 months ago':  
            print test_stamp
            return True
        else:
            return False


response = urllib2.urlopen(url)
html = response.read()
soup = BeautifulSoup(html)
gettweets(soup)
stamp = checkforstamp(soup)
tweets = are_more_tweets(soup)
print 'stamp' + str(stamp)
print 'tweets' +str (tweets)
while (stamp is False) and (tweets is True): 
    b = getnewlink(soup)
    print b
    red = urllib2.urlopen(b)
    html = red.read()
    soup = BeautifulSoup(html)
    gettweets(soup)
    stamp = checkforstamp(soup)
    tweets = are_more_tweets(soup)
print 'done' 

The problem is, after my twitter crawler hits about 3 months of tweets, I would like it to stop going to the next page of a user. However, it does not appear to be doing that. It seems to continually going searching for the next page of tweets. I believe this is due to the fact that checkstamp keeps evaluating to False. Does anyone have any suggestions as to how I can modify the code so that the crawler keeps looking for the next page of tweets as long as there are more tweets (verified by are_more_tweets mechanism) and it hasn’t hit 3 months of tweets yet??? Thanks!

EDIT – Please see below:

from BeautifulSoup import BeautifulSoup
import re
import urllib

url = 'http://mobile.twitter.com/cleversallie'
output = open(r'C:\Python28\testrecursion.txt', 'a') 

def gettweets(soup):
    tags = soup.findAll('div', {'class' : "list-tweet"})#to obtain tweet of a follower
    for tag in tags: 
        a = tag.renderContents()
        b = str (a)
        print(b)
        print('\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'):
            return True
        else:
            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 checkforstamp(soup): # the parser scans a webpage to check if any of the tweets are older than 3 months
    times = soup.findAll('a', {'href': True}, {'class': 'status_link'})
    for time in times:
        stamp = time.renderContents()
        test_stamp = str(stamp)
        if not (test_stamp[0]) in '0123456789':
            continue
        if test_stamp == '3 months ago':
            print test_stamp
            return True
        else:
            return False


response = urllib.urlopen(url)
html = response.read()
soup = BeautifulSoup(html)
gettweets(soup)
stamp = checkforstamp(soup)
tweets = are_more_tweets(soup)
while (not stamp) and (tweets): 
    b = getnewlink(soup)
    print b
    red = urllib.urlopen(b)
    html = red.read()
    soup = BeautifulSoup(html)
    gettweets(soup)
    stamp = checkforstamp(soup)
    tweets = are_more_tweets(soup)
 print 'done' 

Answer 1

Your soup.findall() is picking up an image tag in a link that matches your pattern (has an href attribute and class status-link).

Instead of always returning on the very first link, try:

for time in times:
    stamp = time.renderContents()
    test_stamp = str(stamp)
    print test_stamp
    if not test_stamp[0] in '0123456789':
        continue
    if test_stamp == '3 months ago':  
        return True
    else:
        return False

Which will skip the link if it doesn’t start with a number, so you might actually get to the right link. Keep that print statement in there so you can see if you hit some other kind of link that starts with a number that you also need to filter out.

Edit: What you were doing was always returning on the very first item in times. I changed it so it ignored any links that didn’t start with a number.

However, this would cause it to return None if it didn’t find any links with a number. This would work fine, except you changed while not stamp and tweets to while stamp is False and tweets is True. Change it back to while not stamp and tweets and it will correctly treat None and False as the same, and it should work.