🌐 Mailman 3 December 2005 - Python-list - python.org

generators in Java?
by Tom Sheffler Jan. 2, 2006

Jan. 2, 2006

This may have been discussed before, so I apologize. Does Java have generators? I am aware of the "Iterator" interface, but it seems much more restrictive. Python generators are useful for many more things than simply list enumeration, but the Java Iterator seems limited. Tom

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Re: reading files into dicts
by rbt Jan. 2, 2006

Jan. 2, 2006

Gary Herron wrote: > rbt wrote: > >> What's a good way to write a dictionary out to a file so that it can >> be easily read back into a dict later? I've used realines() to read >> text files into lists... how can I do the same thing with dicts? >> Here's some sample output that I'd like to write to file and then read >> back into a dict: >> >> {'.\\sync_pics.py': 1135900993, '.\\file_history.txt': 1135900994, >> '.\\New Text Document.txt': 1135900552} >> >> > > > A better way, than rolling your own marshaling (as this is called), > would be to use the cPickle module. It can write almost any Python > object to a file, and then read it back in later. It's more efficient, > and way more general than any code you're likely to write yourself. > > The contents of the file are quite opaque to anything except the cPickle > and pickle modules. If you *do* want to roll you own input and output to > the file, the standard lib functions "repr" and "eval" can be used. Repr > is meant to write out objects so they can be read back in and recovered > with eval. If the contents of your dictionary are well behaved enough > (simple Python objects are, and classes you create may be made so), then > you may be able to get away with as little as this: > > f = file('file.name', 'wb') > f.write(repr(myDictionary)) > f.close() > > and > > f = file('file.name', 'rb') > myDictionary = eval(f.read()) > f.close() > > Simple as that is, I'd still recommend the cPickle module. > > As always, this security warning applys: Evaluating arbitrary text > allows anyone, who can change that text, to take over complete control > of your program. So be carefully. > > Gary Herron > > Thanks to everyone for the tips on eval and repr. I went with the cPickle suggestion... this is awesome! It was the easiest and quickest solution performance-wise. Just makes me think, "Wow... how the heck does pickle do that?!" Thanks again, rbt

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Rss/xml namespaces sgmllib, sax, minidom
by Sakcee Jan. 2, 2006

Jan. 2, 2006

I want to build a simple validator for rss2 feeds, that checks basic structure and reports channels , items , and their attributes etc. I have been reading Mark Pilgrims articles on xml.com, diveintopython and someother stuff on sgmllib, sax.handlers and content handlers, xml.dom.minidom why is all of this necessary, what is the difference between all these libraries, it seems to me that I can parse the rss2 feed with any of these libraries.!! ? what is the difference between namespaces and non-namspaces functions in sax.handlers.contenthandler , is the namespace defined like domain names on some website? thanks for any comments

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Amara (XML) problem on Solaris
by Doru-Catalin Togea Jan. 2, 2006

Jan. 2, 2006

Hi! I have ActiveState Python 2.4.1 on Win XP Pro, with Amara 1.1.6. I have a script which works fine. I am trying to run the same script on a Solaris machine, with Python 2.4.2 and Amara 1.1.6. It gives me this error: bash-2.03$ python generateXML.py Traceback (most recent call last): File "generateXML.py", line 16, in ? doc = amara.create_document() AttributeError: 'module' object has no attribute 'create_document' bash-2.03$ Any ideas what is going on? Thanks, Catalin -- <<<< ================================== >>>> << We are what we repeatedly do. >> << Excellence, therefore, is not an act >> << but a habit. >> <<<< ================================== >>>>

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scrape url out of brackets?
by homepricemaps＠gmail.com Jan. 2, 2006

Jan. 2, 2006

any idea how to scrape a url out of a file? for instance if i want to scrape out the href at the end which is "www.cnn.com" is there a way to do it? <tr class="rulesbody"><td width="183" class="rulesbody"><a href="www.cnn.com">

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Pyrex on Darwin, gcc 3.3 optimization trouble
by Will Ware Jan. 1, 2006

Jan. 1, 2006

I am trying to build a Pyrex module on Mac OS X version 10.3.9 (don't know which big cat that is). It already builds fine on Mandrake Linux and Windows XP. I have one source file where gcc hangs if given an optimization setting of -O2 or -O3, but a level of -O works fine. Can anybody suggest an approach to debugging this? I'm comfortable on Linux but I can't find my way out of a paper bag on a Mac. Also, is there a Pyrex or distutils option for limiting the compiler optimization level, ideally on a per-platform basis? Thanks much Will Ware

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how-to POST form data to ASP pages?
by livin Jan. 1, 2006

Jan. 1, 2006

I need to post form data to an ASP page that looks like this on the page itself... <form method='POST'><input src=\icons\devices\coffee-on.gif type='image' align='absmiddle' width=16 height=16 title='Off'><input type='hidden' value='Image' name='Action'><input type='hidden' value='hs.ExecX10ByName "Kitchen Espresso Machine", "Off", 100'></form> I've been trying this but I get a syntax error... params = urllib.urlencode({'hidden': 'hs.ExecX10ByName "Kitchen Espresso Machine", "On", 100'}) urllib.urlopen("http://192.168.1.11:80/hact/kitchen.asp", params) Can someone help out and validate I'm on the right/wrong track and help with the syntax? thanks!

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Filling out forms with python
by Steve Young Jan. 1, 2006

Jan. 1, 2006

Hi, I was wondering if there's a way to fill out forms online using python. Say for example if you wanted to make a search on some search engine without having to actually open a browser or something like that. Thanks. -Steve --------------------------------- Yahoo! DSL Something to write home about. Just $16.99/mo. or less

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bsddb3 locking questions
by Eric S. Johansson Jan. 1, 2006

Jan. 1, 2006

are there any simple examples of how to do record locking with bsddb3? the bsddb3 documentation is reasonably opaque. For example, the DB initialization requires a DBEnv instance for certain environmental features such as locking. but if you want locking, what happens next? I suspect the pattern goes something like the following but it's not clear from the documentation. dbe = DBEnv.open() (does the home directory need to be specified or is there a systemwide default? Is this per application or does a common pool work? dbe.set_lk_detect(...DB_LOCK_YOUNGEST) (but what about db_deadlock??? do I need a cron job?) dbe.lock_id() dbi = db.DB() dbi.open(..) (does the filename specified here need to be the same directory as the homedir in DBEnv or can it in a totally separate location? any advantages to either?) lock = dbe.get_lock() dbi.get/put dbe.lock_put(lock) (the above pattern is for record locking but for database locking, the lock get and put calls would bracket the open/close call) if you close the database, should you automatically close the env or (as I suspect) the database environment can cover one or more database specific incarnations but if you have access different databases, each one should have its own environment. anything else I'm missing? thanks for any guidance, ---eric

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Global Variables in OOP and Python
by newbie Jan. 1, 2006

Jan. 1, 2006

Hello, I have questions about global variables in OOP (in general) and Python (in specific). I understand (I think) that global variables are generally not a good idea. However, if there are variables that need to be accessed by a number of classes that exists in separate namespaces (files), what would be the best way to do this? So far, I have approached the problem by making the variables attributes of one class and passing instances of the class as variables to the other class' methods. The other way I thought of is to create a separate class that consists of the variables and to use the from <file name> import * in all of the files (namespaces) where it is needed. Is there a better way? Are the two ideas presented above acceptable? If so, is one better than the other from an OOP POV?

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