Re: Is there a commas-in-between idiom?
On 2006-11-08, Gabriel Genellina <[EMAIL PROTECTED]> wrote: > At Wednesday 8/11/2006 16:51, Peter van Kampen wrote: > >>""" >>A = B = [] # both names will point to the same list >>""" >> >>I've been bitten by this once or twice in the past, but I have always >>wondered what it was useful for? Can anybody enlighten me? > > As an optimization, inside a method, you can bind an instance > attribute and a local name to the same object: > > def some_action(self): > self.items = items = [] > // following many references to self.items, > // but using items instead. > > Names in the local namespace are resolved at compile time, so using > items is a lot faster than looking for "items" inside self's > namespace each time it's used. Nice example. Thanks, PterK -- Peter van Kampen pterk -- at -- datatailors.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a commas-in-between idiom?
On 2006-11-08, Georg Brandl <[EMAIL PROTECTED]> wrote: > Peter van Kampen schrieb: >> On 2006-11-06, Fredrik Lundh <[EMAIL PROTECTED]> wrote: >>> I've collected a bunch of list pydioms and other notes here: >>> >>> http://effbot.org/zone/python-list.htm >> >> """ >> A = B = [] # both names will point to the same list >> """ >> >> I've been bitten by this once or twice in the past, but I have always >> wondered what it was useful for? Can anybody enlighten me? > > Do you never have a situation where you want to assign the same value > to two variables? In the sense that I might want two empty lists or maybe 2 ints that are initialised as 0 (zero). That's what I (incorrectly) thought A = B = [] did. > Or are you objecting to the fact that both names point to the same > object? I'm not objecting to anything, merely wondering when I could/should use this idiom. There's a nice example in another response (self.items = items = []) > It couldn't be otherwise. Consider: > > X = [] > A = B = X > > What should this do? Copy "X" and assign one copy to A, one to B? Ah yes, I see the error in my ways...I skipped the A = B part too lightly. Thanks, PterK -- Peter van Kampen pterk -- at -- datatailors.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there a commas-in-between idiom?
On 2006-11-06, Fredrik Lundh <[EMAIL PROTECTED]> wrote: > I've collected a bunch of list pydioms and other notes here: > > http://effbot.org/zone/python-list.htm """ A = B = [] # both names will point to the same list """ I've been bitten by this once or twice in the past, but I have always wondered what it was useful for? Can anybody enlighten me? TIA, PterK -- Peter van Kampen pterk -- at -- datatailors.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Apache & Python 500 Error
On 2005-02-02, Christian <[EMAIL PROTECTED]> wrote: > Hello, > > i have an apache 1.3 server with python on debian. Python works fine but > the scripts wont´t work. > > This easy script i want to do on apache: > > #!/usr/bin/python > import os > os.getcwd() > > in apache config i have done this: > > > AddHandler python-program .py > PythonHandler python > Order allow,deny > Allow from all > #PythonDebug On > > > the script is in this directory /var/www/python > > but i get an 500 error everytime, with "every" script You're confusing mod_python and cgi. And you're cgi isn't written properly... Try this to enable cgi for python files: Options +ExecCGI AddHandler cgi-script py Don't forget to restart apache. A proper cgi-file outputs a header with at least the content-type. A header is followed by an empty line. #!/usr/bin/env python import os print "Content-type: text/html" print print os.getcwd() -- Peter van Kampen pterk -- at -- datatailors.com -- http://mail.python.org/mailman/listinfo/python-list
