python timer + urllib2代码错误

Question

I am trying to pull information from a site ever 5 seconds but it doesn't seem to be working and I get errors every time I run it.

Code below:

import urllib2, threading
def readpage():
    data = urllib2.urlopen('http://forums.zybez.net/runescape-2007-prices').read()
    for line in data:
        if 'forums.zybez.net/runescape-2007-prices/player/' in line:
            a = line.split('/runescape-2007-prices/player/'[1])
            print(a.split('">')[0])

t = threading.Timer(5.0, readpage)
t.start()

I get these errors:

Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\Python27\lib\threading.py", line 808, in __bootstrap_inner
    self.run()
  File "C:\Python27\lib\threading.py", line 1080, in run
    self.function(*self.args, **self.kwargs)
  File "C:\Users\Jordan\Desktop\username.py", line 3, in readpage
    data = urllib2.urlopen('http://forums.zybez.net/runescape-2007-prices').rea
()
  File "C:\Python27\lib\urllib2.py", line 127, in urlopen
    return _opener.open(url, data, timeout)
  File "C:\Python27\lib\urllib2.py", line 410, in open
    response = meth(req, response)
  File "C:\Python27\lib\urllib2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File "C:\Python27\lib\urllib2.py", line 448, in error
    return self._call_chain(*args)
  File "C:\Python27\lib\urllib2.py", line 382, in _call_chain
    result = func(*args)
  File "C:\Python27\lib\urllib2.py", line 531, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
HTTPError: HTTP Error 403: Forbidden

Help would be appreciated, thanks!

Answer 1

Did you try opening that url without the thread? The error code says 403: Forbidden, maybe you need authentication for that web page.

Answer 2

This has nothing to do with Python -- the server is denying your requests to that URL.

I suspect that either the URL is incorrect or you've hit some kind of rate limiting and are being blocked.

EDIT: how to make it work

The site is blocking Python's User-Agent . Try this:

import urllib2, threading
def readpage():

    headers = { 'User-Agent' : 'Mozilla/5.0' }
    req = urllib2.Request('http://forums.zybez.net/runescape-2007-prices', None, headers)
    data = urllib2.urlopen(req).read()

    for line in data:
        if 'forums.zybez.net/runescape-2007-prices/player/' in line:
            a = line.split('/runescape-2007-prices/player/'[1])
            print(a.split('">')[0])

Answer 3

The site is rejecting the default User-Agent reported by urllib2. You can change it for all requests in the script using install_opener.

opener = urllib2.build_opener()
opener.addheaders = [('User-agent', 'Mozilla/5.0 (X11; Linux i686; rv:5.0) Gecko/20100101 Firefox/5.0')]
urllib2.install_opener(opener)

You'll also need to split the data from by the site to read it line by line

urllib2.urlopen('http://forums.zybez.net/runescape-2007-prices').read().splitlines()

and change

line.split('/runescape-2007-prices/player/'[1])

to

line.split('/runescape-2007-prices/player/')[1]

Working:

import urllib2, threading

opener = urllib2.build_opener()
opener.addheaders = [('User-agent', 'Mozilla/5.0 (X11; Linux i686; rv:5.0) Gecko/20100101 Firefox/5.0')]
urllib2.install_opener(opener)

def readpage():
    data = urllib2.urlopen('http://forums.zybez.net/runescape-2007-prices').read().splitlines()
    for line in data:
        if 'forums.zybez.net/runescape-2007-prices/player/' in line:
            a = line.split('/runescape-2007-prices/player/')[1]
            print(a.split('">')[0])

t = threading.Timer(5.0, readpage)
t.start()