Pickle in a POST/GET request give EOFError

[Romaric DEFAUX]

Le 16/11/2010 17:47, Romaric DEFAUX a écrit :
> Hi everybody !
>
> First time I write to this mailing list :)
> I started writing in python last week, that's probably why I can't 
> understand the following problem...
>
>
> I create a list called web_site_list.
> This list contain dictionaries called web_site.
> And some values in this dictionaries are list too.
>
> I do that in a function and I return this :
> return pickle.dumps(web_site_list)
>
> This is working fine :)
>
> If I do :
> print "%s" % pickle.loads(system.get_web_site_list())
>
> I've got the right stuffs. For example it returns :
> [{'documentroot_size': '120', 'servername': '---default---', 'client': 
> 'undefined', 'documentroot': '/var/www/', 'client_contact': 
> 'undefined', 'serveralias': []}]
>
> I send this to a web service. I send it like that :
> #I put it in params
> def system_updateweb_site(server, login, password):
>         params = {}
>         params['login'] = login
>         params['password'] = password
>         params['action'] = 'updateweb_site'
>         params['servername'] = get_servername()
>         params['hosted_web_site'] = get_web_site_list()
>         return call_system_ws(server, params)
>
> #Here's how I send it (I tried in GET and POST)
> def call_system_ws(host, params):
>         query_string = urllib.urlencode(params)
> #GET
> #       f = urllib.urlopen("http://%s/ws?%s" % (host, query_string))
> #POST
>         f = urllib.urlopen("http://%s/ws" % (host), query_string)
>         result = f.readline().strip()
>         if result == 'ERROR':
>                 msg = f.readline().strip()
>                 return (False, msg)
>         return (True, result)
>
>
> On the server side :
>                         if action == 'updateweb_site':
>                                 if not (fields.has_key('servername') 
> and fields.has_key('hosted_web_site')):
>                                         raise WSError('missing 
> parameter : servername or hosted_web_site')
>                                         log ('ERROR : missing 
> parameter : servername or hosted_web_site')
>                                 else:
>                                         
> servername=g.db.escape_string(fields['servername'])
>                                         
> hosted_web_site=g.db.escape_string(fields['hosted_web_site'])
>                                         output = 
> systemserver.updateweb_site(cursor, servername, hosted_web_site)
>
> In systemserver.py :
> def updateweb_site(cursor, host, hosted_web_site):
>         web_site_list = pickle.loads(hosted_web_site)
>         return "%s" % (web_site_list)
>
> I catch this error :*
>
> <type 'exceptions.EOFError'>*:
>
> args = ()
> message = ''
>
> Why ?
>
> If I just print hosted_web_site, I get this on my web page :
>
> (lp0\n(dp1\nS\'documentroot_size\'\np2\nS\'120\'\np3\nsS\'servername\'\np4\nS\'default\'\np5\nsS\'client\'\np6\nS\'undefined\'\np7\nsS\'documentroot\'\np8\nS\'/var/www/\'\np9\nsS\'client_contact\'\np10\ng7\nsS\'serveralias\'\np11\n(lp12\nsa. 
>
>
> It's the "pickled view" of
> [{'documentroot_size': '120', 'servername': '---default---', 'client': 
> 'undefined', 'documentroot': '/var/www/', 'client_contact': 
> 'undefined', 'serveralias': []}]
>
> Can someone help me please ? I spend my afternoon to google to try to 
> find a solution...
>
>
> Thanks in advance !!!
>
> Romaric Defaux
>
After entirely rewrite my code to not use Web service but socket (a real 
client/server program) I finally found the problem... And it's not 
linked to the POST or GET method...
It's because of that :
g.db.escape_string(fields['hosted_web_site'])
(escape_string is the function in MySQLdb library)
It escapes the simple quote of the pickled object, and break it...

It's good to know, NEVER escape a pickled object :)

Romaric Defaux


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