Problem checking an existing browser cookie

Nik the Greek nikos.the.gr33k at gmail.com
Mon Aug 30 04:55:56 CEST 2010


On 30 Αύγ, 05:43, MRAB <pyt... at mrabarnett.plus.com> wrote:
> On 30/08/2010 03:07, Nik the Greek wrote:
>
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> > On 30 Αύγ, 04:51, MRAB<pyt... at mrabarnett.plus.com>  wrote:
> >> On 30/08/2010 02:14, Νίκος wrote:
>
> >>> On 29 Αύγ, 21:44, MRAB<pyt... at mrabarnett.plus.com>    wrote:
> >>>> On 29/08/2010 06:34, Νίκος wrote:
>
> >>>>> On 28 Αύγ, 23:15, MRAB<pyt... at mrabarnett.plus.com>      wrote:
> >>>>>> On 28/08/2010 20:37, Íßêïò wrote:
>
> >>>>>>> On 22 Áýã, 10:27, Íßêïò<nikos.the.gr... at gmail.com>        wrote:
> >>>>>>>> On 16 Áýã, 14:31, Peter Otten<__pete... at web.de>        wrote:
>
> >>>>>>>>> Íßêïò wrote:
> >>>>>>>>>> # initializecookie
> >>>>>>>>>> cookie=Cookie.SimpleCookie()
> >>>>>>>>>> cookie.load( os.environ.get('HTTP_COOKIE', '') )
> >>>>>>>>>> mycookie =cookie.get('visitor')
>
> >>>>>>>>>> if ( mycookie and mycookie.value != 'nikos' ) or re.search( r'(cyta|
> >>>>>>>>>> yandex|13448|spider|crawl)', host ) is None:
> >>>>>>>>>>         blabla...
> >>>>>>>>>> ========================
>
> >>>>>>>>>> I checked and Chrome has acookienames visitor with a value ofnikos
> >>>>>>>>>> within.
> >>>>>>>>>> So, i have to ask why the if fails?
>
> >>>>>>>>> Maybe it's because != != ==
>
> >>>>>>>> Iwant ti if code block to be executed only if the browsercookienames
> >>>>>>>> visitor fetched doesnt cotnain the vbalue of 'nikos'
>
> >>>>>>>> Is there somethign wrong with the way i wrote it?
>
> >>>>>>> Please do help me with this too becaus eif i dont solve this my
> >>>>>>> website keeps count my each visit like iam a guest visitor!
>
> >>>>>> Print out mycookie, repr(mycookie.value) (unless mycookie is None) and
> >>>>>> repr(host). Then follow the code yourself to see whether the condition
> >>>>>> is True.
>
> >>>>> print mycookie outputs 'None'
>
> >>>>> Thts weird because i check with the browser and the cookie is there!
>
> >>>> Just because you can see it doesn't mean your code can.
>
> >>>>> print repr(host) outputs '78-236-176.adsl.cyta.gr'
>
> >>>>> repr(mycookie.value) (unless mycookie is None)
>
> >>>>> and also
>
> >>>>> print mycookie.value gives an error too. Maybe there is not a value
> >>>>> method?
>
> >>>> If mycookie is None, then it's not surprising that doesn't have 'value'.
>
> >>>> In summary, mycookie is None, so:
>
> >>>>        mycookie and mycookie.value != 'nikos'
>
> >>>> is false (actually None, which is treated as false).
>
> >>>> host == '78-236-176.adsl.cyta.gr', so:
>
> >>>>        re.search(r'(cyta|yandex|13448|spider|crawl)', host)
>
> >>>> finds 'cyta' and the search returns a match.
>
> >>>> false or false == false
>
> >>>> blabla... isn't executed.
>
> >>> Lets forget the 2nd or argument, ill put it off
>
> >>> so we have this now
>
> >>> if ( mycookie and mycookie.value != 'nikos' ):
> >>>       #do stuff as long as there ins't a cookie names visitor with a
> >>> value of nikos in the broswer
>
> >>> What does it mean practically that the mycookie equals to None?
> >>> That mycookie doesnt exist?
>
> >>> How should i write this if block to mkake sure it checks whether or
> >>> not the cookie exists?
>
> >> Under what conditions do you want to execute the block?
>
> >> This:
>
> >>       mycookie and mycookie.value != 'nikos'
>
> >> will be true if:
>
> >>       there _is_ a cookie, but its value isn't 'nikos'
>
> >> I think that you want is to execute the block if someone else is
> >> visiting. Correct?
>
> > Yes that exactyl right!
>
> > To make sure a cookie is set i have a script names koukos.py
> > containing this:
>
> > ==============================
> > #!/usr/bin/python
> > # -*- coding: utf-8 -*-
>
> > import cgitb; cgitb.enable()
> > import cgi, os, Cookie
>
> > # initialize cookie
> > cookie = Cookie.SimpleCookie()
> > cookie.load( os.environ.get('HTTP_COOKIE', '') )
> > mycookie = cookie.get('visitor')
>
> > htmlBody = []
>
> > # if visitor cookie does exist
> > if ( mycookie and mycookie.value == 'nikos' ):
> >      htmlBody.append('ΑΠΟ ΤΗΝ ΕΠΟΜΕΝΗ ΕΠΙΣΚΕΨΗ ΣΟΥ ΘΑ ΣΕ ΥΠΟΛΟΓΙΖΩ ΩΣ
> > ΕΠΙΣΚΕΠΤΗ ΑΥΞΑΝΟΝΤΑΣ ΤΟΝ ΜΕΤΡΗΤΗ!')
> >      cookie['visitor'] = 'nikos'
> >      cookie['visitor']['expires'] = -1      #this cookie will expire
> > now
> > else:
> >      htmlBody.append('ΑΠΟ ΔΩ ΚΑΙ ΣΤΟ ΕΞΗΣ ΔΕΝ ΣΕ ΕΙΔΑ, ΔΕΝ ΣΕ ΞΕΡΩ, ΔΕΝ
> > ΣΕ ΑΚΟΥΣΑ! ΘΑ ΕΙΣΑΙ ΠΛΕΟΝ Ο ΑΟΡΑΤΟΣ ΕΠΙΣΚΕΠΤΗΣ!!')
> >      cookie['visitor'] = 'nikos'
> >      cookie['visitor']['expires'] = 60*60*24*30*12
>
> > htmlBody.insert(0, 'Content-type: text/html; charset=UTF-8\n')
>
> > print(cookie)
> > print('\n'.join(htmlBody))
> > =============================
>
> > Which i seicth on and off according to my desire if i want to be
> > counted or not!
>
> >> How do you know when it _is_ you? There'll be a cookie which says it's
> >> you?
>
> >> If so, then you want to execute the block if there isn't any cookie, or
> >> if there's a cookie but it doesn't say it's you:
>
> >>       not mycookie or mycookie.value != 'nikos'
>
> > i tried this as you suggested:
>
> > if ( not mycookie or mycookie.value != 'nikos' ) or re.search( r'(msn|
> > yandex|13448|spider|crawl)', host ) is None:
>
> > but the counter keeps increasing although the cookie named visitor on
> > my browser exist and also has the valuie of 'nikos'.
>
> > Why it keeps increasing? Doesn't the if code "sees" that the cookie
> > with a value of "nikos" is present!?!!
>
> Previously your regex was r'(cyta|yandex|13448|spider|crawl)' and you
> said that host was '78-236-176.adsl.cyta.gr', so it matched.
>
> Now your regex is r'(msn|yandex|13448|spider|crawl)'. If host is still
> '78-236-176.adsl.cyta.gr' then of course it doesn't match, so the
> condition is true.

Thats what i want.

If host doesnt contain substringsa of the regex to execute if block.
if it does match i dont want then if block to execute, hence the
counter too.

The reason i had 'cyta' before is because not mycookie or
mycookie.value != 'nikos'  doesn't filter me out.

The problem is what happens with the

not mycookie or mycookie.value != 'nikos'

Since cookie 'visitor' does contain the 'nikos' value why the if code
blck gets executed?



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