Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #54872

Re: Handling 3 operands in an expression without raising an exception

Path csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path <python-python-list@m.gmane.org>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.003
X-Spam-Evidence '*H*': 0.99; '*S*': 0.00; 'charset:iso-8859-7': 0.04; 'assign': 0.07; 'assignment': 0.07; 'detect': 0.07; 'none:': 0.07; 'variables': 0.07; 'string': 0.09; '[0]': 0.09; 'assumed': 0.09; 'exception.': 0.09; 'latter': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'try:': 0.09; 'assume': 0.14; 'block.': 0.16; 'failure.': 0.16; 'host:': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'subject:exception': 0.16; 'subject:expression': 0.16; 'throw': 0.16; 'wrote:': 0.18; 'variable': 0.18; 'skip:p 40': 0.19; 'value.': 0.19; 'written': 0.21; 'putting': 0.22; 'tests': 0.22; 'header:User-Agent:1': 0.23; "haven't": 0.24; 'order.': 0.26; 'pass': 0.26; 'values': 0.27; 'header:X-Complaints-To:1': 0.27; 'idea': 0.28; 'function': 0.29; 'host': 0.29; "doesn't": 0.30; 'code': 0.31; 'lines': 0.31; 'block,': 0.31; 'class': 0.32; 'me?': 0.32; "i'd": 0.34; 'except': 0.35; 'case,': 0.35; 'but': 0.35; 'there': 0.35; 'really': 0.36; 'city:': 0.36; "didn't": 0.36; 'possible': 0.36; 'should': 0.36; 'clear': 0.37; 'skip:o 20': 0.38; 'stopped': 0.38; 'to:addr :python-list': 0.38; 'itself': 0.39; 'sure': 0.39; 'to:addr:python.org': 0.39; 'either': 0.39; 'received:org': 0.40; 'even': 0.60; 'dave': 0.60; 'skip:o 30': 0.61; 'simply': 0.61; 'more': 0.64; 'within': 0.65; 'city': 0.66; 'yes': 0.68; 'line,': 0.68; 'reverse': 0.68; 'default': 0.69; 'fact,': 0.69; 'study': 0.69; '1970,': 0.84; 'nonsense.': 0.84; 'or:': 0.84; 'persistent': 0.84; 'working,': 0.84; 'angel': 0.91; 'dealt': 0.91; 'do:': 0.91; 'vars': 0.91
X-Injected-Via-Gmane http://gmane.org/
To python-list@python.org
From Dave Angel <davea@davea.name>
Subject Re: Handling 3 operands in an expression without raising an exception
Date Fri, 27 Sep 2013 10:43:52 +0000 (UTC)
References <l20njn$uhh$1@dont-email.me> <pan.2013.09.26.08.55.29.461000@nowhere.com> <l210c2$95b$1@dont-email.me> <mailman.345.1380190345.18130.python-list@python.org> <l211m1$f3b$1@dont-email.me> <mailman.348.1380192089.18130.python-list@python.org> <l213jr$p9j$1@dont-email.me> <mailman.350.1380194717.18130.python-list@python.org> <l219tq$o2c$1@dont-email.me> <mailman.354.1380200021.18130.python-list@python.org> <l21d5u$cit$1@dont-email.me> <mailman.355.1380205373.18130.python-list@python.org> <l21p2r$ilf$1@dont-email.me> <l224n6$oak$1@dont-email.me> <l22bkl$9ds$1@dont-email.me> <mailman.372.1380236161.18130.python-list@python.org> <l23ijp$jka$1@dont-email.me>
Mime-Version 1.0
Content-Type text/plain; charset=ISO-8859-7
Content-Transfer-Encoding 8bit
X-Gmane-NNTP-Posting-Host 174.32.174.35
User-Agent XPN/1.2.6 (Street Spirit ; Linux)
X-BeenThere python-list@python.org
X-Mailman-Version 2.1.15
Precedence list
List-Id General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive <http://mail.python.org/pipermail/python-list/>
List-Post <mailto:python-list@python.org>
List-Help <mailto:python-list-request@python.org?subject=help>
List-Subscribe <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups comp.lang.python
Message-ID <mailman.375.1380278663.18130.python-list@python.org> (permalink)
Lines 109
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1380278663 news.xs4all.nl 15964 [2001:888:2000:d::a6]:38926
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:54872

Show key headers only | View raw


On 27/9/2013 05:19, Νίκος wrote:

> Στις 27/9/2013 1:55 πμ, ο/η Dave Angel έγραψε:

>>
>> Simply assign the default values BEFORE the try block, and use pass as
>> the except block.
>>
>> That still doesn't get around the inadvisability of putting those 3
>> lines in the try block.
>>
>> You still haven't dealt with the gt assignment and its possible
>> exception.
>>
> Yes gi must be removed form within the try block because iam tesign it 
> for failure.

Then why don't you do it below?

>
> I'am not sure what you mean though when you say:
>
>> Simply assign the default values BEFORE the try block, and use pass as
>> the except block.
>
> Can you please make it more clear for me?
>
> This is my code as i have it at the moment:
>
> ipval = ( os.environ.get('HTTP_CF_CONNECTING_IP') or 
> os.environ.get('REMOTE_ADDR', "Cannot Resolve") )
> try:
> 	gi = pygeoip.GeoIP('/usr/local/share/GeoIPCity.dat')
> 	city = gi.time_zone_by_addr( ipval )
> 	host = socket.gethostbyaddr( ipval ) [0]
> except socket.gaierror as e:
> 	city = "Άγνωστη Πόλη"
> 	host = "Άγνωστη Προέλευση"

ipval = ( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR', "Cannot Resolve") )
city = "Άγνωστη Πόλη"
host = "Άγνωστη Προέλευση"
try:
	city = gi.time_zone_by_addr( ipval )
	host = socket.gethostbyaddr( ipval ) [0]
except socket.gaierror as e:
	pass

>
> Or even better since i actually use 3 vars inside the try block it would 
> be really neat to be able to detect which far failed and assign a 
> specific value variable failed depended.

ipval = ( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR', "Cannot Resolve") )
city = None
host = None
try:
	city = gi.time_zone_by_addr( ipval )
	host = socket.gethostbyaddr( ipval ) [0]
except socket.gaierror as e:
	if not city:
		city = "Άγνωστη Πόλη"
	if not host:
		host = "Άγνωστη Προέλευση"

or:

ipval = ( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR', "Cannot Resolve") )
city = None
host = None
try:
	city = gi.time_zone_by_addr( ipval )
	host = socket.gethostbyaddr( ipval ) [0]
except socket.gaierror as e:
	if not host:
		host = "Άγνωστη Προέλευση"
		if not city:
			city = "Άγνωστη Πόλη"

Note that in that last case, I tested the variables in the reverse
order.  Note also on both of these that I assumed that None is not a
reasonable value for either of those.  In fact, I also assume that an
empty string is not a reasonable value.  If I didn't like the latter
assumption, I'd have used tests like  if host is None:

>
> IF it can also be written in one-line afteer the excpect would be even 
> better. Call me persistent but when i can write somethign in 1-line i 
> wou;d prefer it over 3-lines.

Ridiculous.  But if you like code golf, you can always do:

city, host = "Άγνωστη Πόλη", "Άγνωστη Προέλευση"

You should study APL.  Many functions were written in one line, with
twenty lines of explanation.  The function itself was considered
unreadable nonsense. And if a function stopped working, general wisdom
was to throw it out, and re-implement the explanation. I studied it
briefly in class in 1970, and have no idea if there are current
implementations.


-- 
DaveA

Back to comp.lang.python | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 10:26 +0300
  Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-26 10:48 +0300
    Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 10:51 +0300
      Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-26 11:12 +0300
        Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 11:39 +0300
          Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 11:46 +0300
            Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 11:50 +0300
              Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-26 12:20 +0300
          Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-26 12:04 +0300
            Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 12:45 +0300
          Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 11:07 +0200
            Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 12:31 +0300
              Re: Handling 3 operands in an expression without raising an exception Maarten <maarten.sneep@knmi.nl> - 2013-09-26 02:52 -0700
              Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 12:01 +0200
              Re: Handling 3 operands in an expression without raising an exception "James Harris" <james.harris.1@gmail.com> - 2013-09-26 11:53 +0100
          Re: Handling 3 operands in an expression without raising an exception alex23 <wuwei23@gmail.com> - 2013-09-27 10:05 +1000
        Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-26 18:41 +1000
        Re: Handling 3 operands in an expression without raising an exception Tim Golden <mail@timgolden.me.uk> - 2013-09-26 09:47 +0100
  Re: Handling 3 operands in an expression without raising an exception Nobody <nobody@nowhere.com> - 2013-09-26 09:55 +0100
    Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 12:56 +0300
      Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 12:12 +0200
        Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 13:18 +0300
          Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 12:41 +0200
            Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 13:51 +0300
              Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 13:07 +0200
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 14:25 +0300
                Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 13:47 +0200
                Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-26 14:42 +0000
              Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-26 11:24 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 15:39 +0300
                Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-26 14:53 +0200
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 16:34 +0300
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-26 14:22 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-26 19:58 +0300
                Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-26 20:16 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 01:14 +0300
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-26 22:55 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 12:19 +0300
                Re: Handling 3 operands in an expression without raising an exception Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-27 09:26 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 13:04 +0300
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-27 10:43 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 14:15 +0300
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-27 12:17 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 15:51 +0300
                Re: Handling 3 operands in an expression without raising an exception rusi <rustompmody@gmail.com> - 2013-09-28 10:29 -0700
                Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-27 15:16 +0000
                Re: Handling 3 operands in an expression without raising an exception Grant Edwards <invalid@invalid.invalid> - 2013-09-27 16:04 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-27 19:47 +0300
                Re: Handling 3 operands in an expression without raising an exception Neil Cerutti <neilc@norwich.edu> - 2013-09-27 16:56 +0000
                Re: Handling 3 operands in an expression without raising an exception Grant Edwards <invalid@invalid.invalid> - 2013-09-27 17:00 +0000
                Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-27 13:19 -0400
                Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-27 18:32 +0100
                Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-27 18:49 +0000
                Re: Handling 3 operands in an expression without raising an exception Grant Edwards <invalid@invalid.invalid> - 2013-09-27 18:54 +0000
                Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-27 15:21 -0400
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 01:06 +0300
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-27 22:26 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 12:33 +0300
                Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-28 20:19 +1000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 16:23 +0300
                Re: Handling 3 operands in an expression without raising an exception Andreas Perstinger <andipersti@gmail.com> - 2013-09-28 17:02 +0200
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 19:14 +0300
                Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-28 18:53 +0100
                Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-28 14:21 -0400
                Re: Handling 3 operands in an expression without raising an exception Zero Piraeus <z@etiol.net> - 2013-09-28 15:38 -0300
                Re: Handling 3 operands in an expression without raising an exception Neil Cerutti <neilc@norwich.edu> - 2013-09-30 11:32 +0000
                Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-30 21:53 +1000
                Re: Handling 3 operands in an expression without raising an exception Neil Cerutti <neilc@norwich.edu> - 2013-09-30 12:56 +0000
                Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-28 19:45 +0100
                Re: Handling 3 operands in an expression without raising an exception Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-28 19:20 +0000
                Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-29 09:04 +1000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 10:35 +0300
                Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-29 12:35 +0300
                Re: Handling 3 operands in an expression without raising an exception Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-09-29 09:48 +0000
                Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-29 14:04 +0300
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 14:14 +0300
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-29 11:27 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 14:34 +0300
                Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-29 21:15 +0000
                Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-30 16:07 +0100
                Re: Handling 3 operands in an expression without raising an exception Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-09-29 15:24 +0300
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-29 09:50 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 13:17 +0300
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-29 10:57 +0000
                Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-29 23:58 +1000
                Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-29 21:01 +0000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-29 14:06 +0300
                Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-29 12:48 +0200
                Re: Handling 3 operands in an expression without raising an exception Piet van Oostrum <piet@vanoostrum.org> - 2013-09-29 13:24 -0400
                Re: Handling 3 operands in an expression without raising an exception MRAB <python@mrabarnett.plus.com> - 2013-09-29 18:44 +0100
                Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-29 14:45 -0400
                Re: Handling 3 operands in an expression without raising an exception Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-09-30 16:05 +0100
                Re: Handling 3 operands in an expression without raising an exception Ben Finney <ben+python@benfinney.id.au> - 2013-09-29 11:35 +1000
                Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-28 11:59 +1000
                Re: Handling 3 operands in an expression without raising an exception Νίκος <nikos.gr33k@gmail.com> - 2013-09-28 12:14 +0300
                Re: Handling 3 operands in an expression without raising an exception Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-09-28 15:53 +0200
                Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-28 12:15 -0400
                Re: Handling 3 operands in an expression without raising an exception Robert Kern <robert.kern@gmail.com> - 2013-09-28 12:18 +0100
                Re: Handling 3 operands in an expression without raising an exception giacomo boffi <pecore@pascolo.net> - 2013-09-29 17:28 +0200
                Re: Handling 3 operands in an expression without raising an exception Joel Goldstick <joel.goldstick@gmail.com> - 2013-09-29 12:07 -0400
                Re: Handling 3 operands in an expression without raising an exception giacomo boffi <pecore@pascolo.net> - 2013-09-29 23:39 +0200
                Re: Handling 3 operands in an expression without raising an exception giacomo boffi <pecore@pascolo.net> - 2013-09-29 23:49 +0200
                Re: Handling 3 operands in an expression without raising an exception Chris Angelico <rosuav@gmail.com> - 2013-09-30 02:18 +1000
                Re: Handling 3 operands in an expression without raising an exception Dave Angel <davea@davea.name> - 2013-09-26 20:37 +0000
      Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-26 14:38 +0000
      Re: Handling 3 operands in an expression without raising an exception Denis McMahon <denismfmcmahon@gmail.com> - 2013-09-26 14:38 +0000
  Re: Handling 3 operands in an expression without raising an exception Gene Heskett <gheskett@wdtv.com> - 2013-09-29 13:32 -0400

csiph-web