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Problem checking an existing browser cookie

MRAB python at mrabarnett.plus.com
Sun Aug 29 22:43:07 EDT 2010 
On 30/08/2010 03:07, Nik the Greek wrote:
> 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.
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