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• Python __setattr__ and __getattr__ for global scope?

  - by KT

  Suppose I need to create my own small DSL that would use Python to describe a certain data structure. E.g. I'd like to be able to write something like f(x) = some_stuff(a,b,c) and have Python, instead of complaining about undeclared identifiers or attempting to invoke the function some_stuff, convert it to a literal expression for my further convenience. It is possible to get a reasonable approximation to this by creating a class with properly redefined __getattr__ and __setattr__ methods and use it as follows: e = Expression() e.f[e.x] = e.some_stuff(e.a, e.b, e.c) It would be cool though, if it were possible to get rid of the annoying "e." prefixes and maybe even avoid the use of []. So I was wondering, is it possible to somehow temporarily "redefine" global name lookups and assignments? On a related note, maybe there are good packages for easily achieving such "quoting" functionality for Python expressions?

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• Get the affinity of a SQLite column on Android

  - by Neil Traft

  The SQLite C library has a method, sqlite3_column_decltype(). But I cannot find any place where the Android SQLite API makes this method available. Is there any way to get the declared type of a column without running any SQL (i.e. can I avoid using PRAGMA table_info)? I could have used AbstractWindowedCursor.isBlob(), but it says that it will also return true if the field is NULL. I need something that will guarantee me a value equal to the column's declared type.

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• Issues running python scripts in Command Prompt (Specifically with command line arguments)?

  - by dmanatunga

  I am trying to run my python scripts in DOS without calling python.exe first. I am specifically doing this in relation to running django-admin.py. I have C:\Python26 and C:\Python26\Scripts in my PATH. However, if I try running django-admin.py by doing: django-admin.py startproject helloworld I get the message: Type 'django-admin.py help' for usage. Now, after some experimentation, I realized the problem is that the secondary arguments to these scripts are not being passed for some reason, since I tried it with a some other python scripts I have. I know I could avoid this problem by simply doing: python C:\Python26\Scripts\django-admin.py startproject helloworld But I know it should be possible to run the first command only and get it to work, because I had it working before. I've looked everywhere, and not many places have been helpful so any idea would be useful for me at this point.

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• Updating Activity UI from Different Activity Method?

  - by stormin986

  I have a tab widget where one of the tabs is a chat-type feature. I want to update the chat data at an interval (variable depending on whether the chat tab is active or not). The best approach seemed to be using an AsyncTask in my main TabActivity class, as that would avoid any issues of the chat activity being destroyed while in the background, while an AsyncTask was running. I wanted to ensure that the Activity isn't destroyed and recreated, thus causing my AsyncTask to be unable to modify the actual active Activity's data. However, now that my AsyncTask is in the TabActivity activity, I don't have a direct way to call my Chat's ListAdapter notifyDataSetChanged() from my onPostExecute() method anymore. Is there a way to get a reference to a given Tab's current Activity from the TabHost/TabActivity? Or, alternatively, can I assume my chat activity will never be destroyed as a child activity of the TabActivity activity (well, never destroyed while the TabActivity is active at least), and then just put the AsyncTask in the Chat Activity?

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• VB.NET generates properties in the release build

  - by dattebayo

  I have a form and i drag and drop a control in VB.NET. I have a line say, private WithEvents radioButton RadioButton Also, I have a handler like, private void click(.....) Handles radioButton.Click { ... } Now, When I build this is .NET 3.5 in release mode, and see the generated code in reflector tool, the code is something like, Private Overridable Property radioButton As RadioButton . . . <AccessedThroughProperty("radioButton")> _ Private _radioButton As RadioButton Can someone tell me what is going on here? And how do I avoid the generation of new properties and fields? -datte

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• does it make sense to send password information during email communication from websites

  - by Samuel

  Most of the online sites on registration do send a link to activate the site and on any further correspondence with the end user they provide information about the site and also provide the login credentials with password in clear text (as given below) Username - [email protected] Password - mysecretpassword What would you do in such a case? From a usability perspective does it make sense to send the password information in clear text or should you just avoid sending this information. I was under the impression that most of the passwords are MD5 hashed before storing in the database and hence the service provider will not have any access to clear text passwords, is this a security violation?

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• Keeping track of dirty blocks on a block device

  - by mikeY

  I'm looking for a way to keep track of what blocks on a block device are modified after a point in time. How I eventually want to use this for is to keep two 2TB disks in sync, one which only comes online (connected through USB) once a month. Without knowing what blocks have been modified, I have to go through the whole 2TB every time. I'm using a recent GNU/Linux OS and have C and Python experience. I'm hoping to avoid writing kernel level code as I don't have any experience in that area whatsoever. My current theory is that there should be some hooks somewhere where my code can get called when a disk flush is performed. Any ideas?

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• Can I change the database server and database a report is pointing to dynamically?

  - by Randy Minder

  I have a Crystal 2008 report that will be deployed to an InfoView server. There are four different databases the user might want to execute the report against. Each of the four databases have exactly the same schema. Only the data in each is different. Each database corresponds to a plant we have around the world. Instead of creating four different reports (each one connected to one of the four databases), am I able to dynamically change the server/database the report hits based on a value the user enters into a parameter? I'm really trying to avoid having to create four identical reports except for the database connection on each. If this isn't possible, how do developers typically deal with this sort of scenario? I would imagine it's fairly common. Thanks very much.

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• C++ containers on classes, returning pointers

  - by otneil

  Hello, I'm having some trouble to find the best way to accomplish what I have in mind due to my inexperience. I have a class where I need to a vector of objects. So my first question will be: is there any problem having this: vector< AnyType container* and then on the constructor initialize it with new (and deleting it on the destructor)? Another question is: if this vector is going to store objects, shouldn't it be more like vector< AnyTipe* so they could be dynamically created? In that case how would I return an object from a method and how to avoid memory leaks (trying to use only STL)?

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• $.get sends prototype functions in request URL?

  - by pimvdb

  I have some prototype functions added to Object which in my opinion were practical in certain scenarios. However, I noticed that when I executed a $.get, the prototype functions are handled as data members and are sent like http://...?prototypefunc=false. This is rather useless as I don't supply these as data members, but they are added to the query string. To be exact, I have this code: Object.prototype.in = function() { for(var i=0; i<arguments.length; i++) if(arguments[i] == this) return true; return false; } $.get('http://localhost/test.php', {'test': 'foo'}, function(text) { }); The corresponding URL constructed is: http://localhost/test.php?test=foo&in=false How can I avoid this?

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• Importing a spreadsheet, but having trouble.

  - by Chris Phelps

  I have a form that allows a user to import a spreadsheet. This spreadsheet is generally static when it comes to column headers, but now the users want to be able to include an optional column (called Notes). My code crashes when I try to read the column from the spreadsheet if it doesn't exist. Dim objCommand As New OleDbCommand() objCommand = ExcelConnection() 'function that opens spreadsheet and returns objCommand Dim reader As OleDbDataReader reader = objCommand.ExecuteReader() While reader.Read() Dim Employee As String = Convert.ToString(reader("User")) Dim SerialNUM As String = Convert.ToString(reader("serialno")) **Dim Notes As String = Convert.ToString(reader("notes"))** If the spreadsheet contains a Notes column, all goes well. If not, crash. How can I check to see if the Notes column exists in the spreadsheet to avoid the crash?

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• What is the effect on record size of reordering columns in PostgreSQL?

  - by Summer

  Since Postgres can only add columns at the end of tables, I end up re-ordering by adding new columns at the end of the table, setting them equal to existing columns, and then dropping the original columns. So, what does PostgreSQL do with the memory that's freed by dropped columns? Does it automatically re-use the memory, so a single record consumes the same amount of space as it did before? But that would require a re-write of the whole table, so to avoid that, does it just keep a bunch of blank space around in each record? Thanks! ~S

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• Paging Recordsets from SQL Serverside

  - by Jonno

  I've been banging my head off this one for a while. I want to call 1k records from a SQL database and page them per 100. In classic ASP (where I'm moving from) this was dead easy to do with ADODB but with VB using ADO.net I can't find a single way that doesn't involve stored procs (which I want to avoid for now). It seems really stupid to call all 1k and sort it programmatically. Edit: It's SQL Server 2005 / .net 4.0 / Visual Studio 2010. Edit 2: Just to reiterate, I have Googled extensively and don't want to use stored procedures. There are many ways to get paged data but everything I see involves paging the data in the program rather than from the server.

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• bitfield mask calculation macro

  - by Aidan Cully

  We have a set of C macros, here, for using the preprocessor to do bitfield operations, and we run into warnings when attempting to use these macros in visual studio. The problem can be demonstrated very easily: #define BITFIELD_WIDTHMASK(Width) \ ((Width) >= 32 ? ~0x0ul : (1ul << (Width)) - 1) unsigned long foo(void) { return BITFIELD_WIDTHMASK(32); } Compiling this with MSVC yields the warning: test.c(12) : warning C4293: '<<' : shift count negative or too big, undefined behavior This isn't a behavior problem - the << operator won't be used in this case, and that should be detected at compile time. But does anyone have any suggestions about how to rewrite the macro to avoid the warning? Or, failing that, how to redesign the macro interface for this? Thanks in advance

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• [Symfony] Admin generator and i18n

  - by David

  I have read lots of questions about i18n, but I haven't found any about performance. I have a simple backend app listing the contents of an ads table. These ads have a category, that is translated in some languages (it's defined as i18n in the Doctrine schema). So, when I add a "table_method" in my generator.yml to include de Category table, it reduces the number of queries, but there are yet some of them referencing i18n translation tables. So, if I add the category Translation table to the query, it reduces even more the queries BUT it increases the processing time considerably. Why this time penalty? Just because of the translation table? And why isn't the filter using this method to avoid so many translation queries as well? I mean, if I want to filter by category, it is making one query per category to include the translation table. Why??

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• Audio input via HTML5?

  - by tibbon

  We have a VoIP application imVOX, and we are looking at various ways of expanding our reach. Part of that is writing an HTML5 application, but it requires the use of audio input from the browser (and also push to talk buttons from the browser, even if another app is focused). On the audio side, with HTML5 is there any way of taking audio input from the browser to compress and send to our servers? I know with Flash such is possible, but we're trying to avoid flash for mobile compatibility and generally looking toward the future.

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• Can I join between two MySQL tables stores on separate machines?

  - by CuriousCoder

  I have a relatively light query that needs information from a local MySQL table along with another MySQL table which is stored on a physically separate machine (on the same network). I'm keen to avoid setting up replication just to facilitate this light query that only needs executed once a day. Is there any way that I can join with a table on a remote machine using one query? Or run a SELECT INTO into a local table. Notes I'm using C# & .NET 4.

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• Is window.location.href = 'some_page.html' followed by search engines?

  - by Arkaaito

  Currently our website uses links to allow the user to change their locale. The problem with this is that you get a lot of random outlinks from each page on the site to... the same page, in other languages. When a search engine traverses this, it gets an excessively complex view of the site. We were going to change it to a form post to avoid this. However, it seems to me that we should just be able to change it to an onclick="window.location.href='change_my_language.php'" rather than an href="change_my_language.php". Am I right? Or do the major search engines scan for and follow this sort of thing nowadays?

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• How to make a file with .pt extension, with xml syntax highlighting and vim's plugin snipmate load p

  - by Somebody still uses you MS-DOS

  I have the following in my .vimrc: au BufNewFile,BufRead *.pt set filetype=xml This is needed because although I'm editing a file with *.pt extension, it's indeed a valid xml file: setting the filetype like this I can have syntax highlighting. I'm using vim's snipmate plugin, and tried to create pt.snippets to specific needs since these files are Zope Page Templates (ZPT with TAL). Now, I have a problem: I don't want to create these snippets in xml.snippets, since they aren't really generic xml snippets, but my *.pt files are set to xml, so when I define my pt snippets they aren't loaded unless I run :set filetype=pt on my pt file on vim - but then I lose syntax highlighting. I would like to be able to have a pt file, with xml syntax highlighting, to be able to load a pt.snippets file from snipmate. How can I do it? (I would like to avoid putting my snippets in a generic snippet file, I would like it to be present only in pt.snippets to be easier to maintain.)

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• How can I close a SimpleModal dialog when the user clicks the Back button?

  - by Wally Hartshorn

  When a user clicks on a button or link, I use the SimpleModal jQuery plugin to display a dialog to overlay the entire page, preventing the user from clicking another button or link during the delay before the next page loads. (I'd like to avoid this, but that's an issue for another day.) After the next page displays, if the user clicks the Back button, the previous page still has the SimpleModal overlay displayed, preventing them from using the page. This is a problem. How can I cause the SimpleModal dialog to close automatically either when the leaves the page or when the user clicks the Back button to return to the page? I tried this without success: $("body").unload(function() { $.modal.close(); }); Thanks! Wally

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• Remove .php extension (explicitly written) for friendly URL

  - by miquel

  htaccess to remove the .php extension of my site's files. RewriteEngine on RewriteBase / RewriteCond %{SCRIPT_FILENAME} !-d RewriteCond %{SCRIPT_FILENAME} !-f RewriteRule ^(.*)$ $1.php [L,QSA] Now, if I go to my site www.mysite.com/home works fine, it redirects to home.php but the URL is still friendly. But if I write this URL: www.mysite.com/home.php The home.php is served, and the URL is not friendly. How can I avoid this behavior? I want that if the user writes www.mysite.com/home.php, the URL displayed in the URL bar be www.mysite.com/home

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• Does Python Django support custom SQL and denormalized databases with no Foreign Key relationships?

  - by Jay

  I've just started learning Python Django and have a lot of experience building high traffic websites using PHP and MySQL. What worries me so far is Python's overly optimistic approach that you will never need to write custom SQL and that it automatically creates all these Foreign Key relationships in your database. The one thing I've learned in the last few years of building Chess.com is that its impossible to NOT write custom SQL when you're dealing with something like MySQL that frequently needs to be told what indexes it should use (or avoid), and that Foreign Keys are a death sentence. Percona's strongest recommendation was for us to remove all FKs for optimal performance. Is there a way in Django to do this in the models file? create relationships without creating actual DB FKs? Or is there a way to start at the database level, design/create my database, and then have Django reverse engineer the models file?

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• How to fix this python error? RuntimeError: dictionary changed size during iteration

  - by aF

  Hello, it gives me this error: Exception in thread Thread-163: Traceback (most recent call last): File "C:\Python26\lib\threading.py", line 532, in __bootstrap_inner self.run() File "C:\Python26\lib\threading.py", line 736, in run self.function(*self.args, **self.kwargs) File "C:\Users\Public\SoundLog\Code\Código Python\SoundLog\SoundLog.py", line 337, in getInfo self.data1 = copy.deepcopy(Auxiliar.DataCollection.getInfo(1)) File "C:\Python26\lib\copy.py", line 162, in deepcopy y = copier(x, memo) File "C:\Python26\lib\copy.py", line 254, in _deepcopy_dict for key, value in x.iteritems(): RuntimeError: dictionary changed size during iteration while executing my python program. How can I avoid this to happen? Thanks in advance ;)

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• BASH Expression to replace beginning and ending of a string in one operation?

  - by swestrup

  Here's a simple problem that's been bugging me for some time. I often find I have a number of input files in some directory, and I want to construct output file names by replacing beginning and ending portions. For example, given this: source/foo.c source/bar.c source/foo_bar.c I often end up writing BASH expressions like: for f in source/*.c; do a="obj/${f##*/}" b="${a%.*}.obj" process "$f" "$b" done to generate the commands process "source/foo.c" "obj/foo.obj" process "source/bar.c "obj/bar.obj" process "source/foo_bar.c "obj/foo_bar.obj" The above works, but its a lot wordier than I like, and I would prefer to avoid the temporary variables. Ideally there would be some command that could replace the beginning and ends of a string in one shot, so that I could just write something like: for f in source/*.c; do process "$f" "obj/${f##*/%.*}.obj"; done Of course, the above doesn't work. Does anyone know something that will? I'm just trying to save myself some typing here.

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• Secure password transmission over unencrypted tcp/ip

  - by academicRobot

  I'm in the designing stages of a custom tcp/ip protocol for mobile client-server communication. When not required (data is not sensitive), I'd like to avoid using SSL for overhead reasons (both in handshake latency and conserving cycles). My question is, what is the best practices way of transmitting authentication information over an unencrypted connection? Currently, I'm liking SRP or J-PAKE (they generate secure session tokens, are hash/salt friendly, and allow kicking into TLS when necessary), which I believe are both implemented in OpenSSL. However, I am a bit wary since I don't see many people using these algorithms for this purpose. Would also appreciate pointers to any materials discussing this topic in general, since I had trouble finding any.

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