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• delete all records except the id I have in a python list

  - by jay_t

  Hi all, I want to delete all records in a mysql db except the record id's I have in a list. The length of that list can vary and could easily contain 2000+ id's, ... Currently I convert my list to a string so it fits in something like this: cursor.execute("""delete from table where id not in (%s)""",(list)) Which doesn't feel right and I have no idea how long list is allowed to be, .... What's the most efficient way of doing this from python? Altering the structure of table with an extra field to mark/unmark records for deletion would be great but not an option. Having a dedicated table storing the id's would indeed be helpful then this can just be done through a sql query... but I would really like to avoid these options if possible. Thanks,

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• How to know if the website being scraped has changed?

  - by Lost_in_code

  I'm using PHP to scrape a website and collect some data. It's all done without using regex. I'm using php's explode() method to find particular HTML tags instead. It is possible that if the structure of the website changes (CSS, HTML), then wrong data may be collected by the scraper. So the question is - how do I know if the HTML structure has changed? How to identify this before storing any data to my database to avoid wrong data being stored.

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• Why can't I enforce derived classes to have parameterless constructors?

  - by FrisbeeBen

  I am trying to do the following: public class foo<T> where T : bar, new() { public foo() { _t = new T(); } private T _t; } public abstract class bar { public abstract void someMethod(); // Some implementation } public class baz : bar { public overide someMethod(){//Implementation} } And I am attempting to use it as follows: foo<baz> fooObject = new foo<baz>(); And I get an error explaining that 'T' must be a non-abstract type with a public parameterless constructor in order to use it as parameter 'T' in the generic type or method. I fully understand why this must be, and also understand that I could pass a pre-initialized object of type 'T' in as a constructor argument to avoid having to 'new' it, but is there any way around this? any way to enforce classes that derive from 'bar' to supply parameterless constructors?

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• Mysterious different conversion to string[] of seemingly same input data

  - by Roman Kuzmin

  During investigation of some problem I found that the reason was unexpected different conversion to string[] of seemingly same input data. Namely, in the code below two commands both return the same two items File1.txt and File2.txt. But conversion to string[] gives different results, see the comments. Any ideas why is it? This might be a bug. If anybody also thinks so, I’ll submit it. But it would nice to understand what’s going on and avoid traps like that. # *** WARNING # *** Make sure you do not have anything in C:\TEMP\Test # *** The code creates C:\TEMP\Test with File1.txt, File2.txt # Make C:\TEMP\Test and two test files $null = mkdir C:\TEMP\Test -Force 1 | Set-Content C:\TEMP\Test\File1.txt 1 | Set-Content C:\TEMP\Test\File2.txt # This gets just file names [string[]](Get-ChildItem C:\TEMP\Test) # This gets full file paths [string[]](Get-ChildItem C:\TEMP\Test -Include *) # Output: # File1.txt # File2.txt # C:\TEMP\Test\File1.txt # C:\TEMP\Test\File2.txt

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• Why do I have to give an identifier?

  - by Knowing me knowing you

  In code: try { System.out.print(fromClient.readLine()); } catch(IOException )//LINE 1 { System.err.println("Error while trying to read from Client"); } In code line marked as LINE 1 compiler forces me to give an identifier even though I'm not using it. Why this unnatural constrain? And then if I type an identifier I'm getting warning that identifier isn't used. It just doesn't make sense to me, forcing a programmer to do something unnecesarry and surplus. And after me someone will revise this code and will be wondering if I didn't use this variable on purpouse or I just forgot. So in order to avoid that I have to write additional comment explaining why I do not use variable which is unnecessary in my code. Thanks

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• Help getting PHP sessions to persist after being taken off-site

  - by Rob

  Hi, we're working on a payment gateway system with PHP. We use sessions to store the shopping cart data. The system takes you off-site to the payment processor's site, and then return you to your site. On most hosts, we have no issues when we arrive back at our site and having the session data still be there. On those with an issue, turning off the PHP session referer_check has worked in the past. We don't really want to have to include the PHPSESSID as a GET variable, and hope to avoid that. What I'm looking for is what other server configurations would cause the session to be killed, and any other workarounds there might be. Thanks for your help.

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• maintain formatting entered into an html form?

  - by NickG77

  Im setting up a web form, and I'm trying to have it where visitors can paste their resumes into a text area. Then I want to email the info using php mail(). But the resume info is just stored in the variable as one long string with no formatting. Is there a way I can send the pasted resume text to the client in the resume format? Maintaining all the line breaks and stuff? He wants to avoid having people upload resumes.

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• Is there a way to test if a scalar has been stringified or not?

  - by Yobert

  I am writing a thing to output something similar to JSON, from a perl structure. I want the quoting to behave like this: "string" outputs "string" "05" outputs "05" "5" outputs "5" 5 outputs 5 05 outputs 5, or 05 would be acceptable JSON::XS handles this by testing if a scalar has been "stringified" or not, which I think is very cool. But I can't find a way to do this test myself without writing XS, which I'd rather avoid. Is this possible? I can't find this anywhere on CPAN without finding vast pedantry about Scalar::Util::looks_like_number, etc which completely isn't what I want. The only stopgap I can find is Devel::Peek, which feels evil. And also, just like JSON::XS, I'm fine with this secenario: my $a = 5; print $a."\n"; # now $a outputs "5" instead of 5)

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• How to add a web service reference in a DLL

  - by dan

  I'm creating a DLL with a reference to web services (I don't have the choice to do so) but I have to add web service references to the project that uses the DLL for it to work. Example, I have the DLL called API.DLL that calls a web service called WebService.svc that I want to use in a project called WinForm. First, I have to add a "Service Reference" to WebService.svc in API.DLL. Then, I add a reference API.DLL to WinForm but it doesn't work unless I also add a service reference to WebService.svc in WinForm. What can I do to avoid that last step?

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• WPF Logical Tree - bottom up vs. top down

  - by Dor Rotman

  Hello, I've read the MSDN article about the layouts pass, that states: When a node is added or removed from the logical tree, property invalidations are raised on the node's parent and all its children. As a result, a top-down construction pattern should always be followed to avoid the cost of unnecessary invalidations on nodes that have already been validated. Now lets assume I do this. Won't the users see the control tree populate itself and the layout change several times during the control creation process? I want the whole control tree to just appear completely full. Thanks!

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• Should I put a try-finally block after every Object.Create?

  - by max

  I have a general question about best practice in OO Delphi. Currently, I put try-finally blocks anywhere I create an object to free that object after usage (to avoid memory leaks). E.g.: aObject := TObject.Create; try aOBject.AProcedure(); ... finally aObject.Free; end; instead of: aObject := TObject.Create; aObject.AProcedure(); .. aObject.Free; Do you think it is good practice, or too much overhead? And what about the performance?

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• 1120: Why can't it access the variable?

  - by Oden

  I'm new at as3, maybe thats the reason why i don't understand, why the setInterval causes an error. <mx:Script> <![CDATA[ import flash.utils.setInterval; import mx.controls.Alert; [Bindable] public var MyInt:int = 500; setInterval(function():void{ ++MyInt; },1000); ]]> </mx:Script> I have a label where the value of MyInt gets visible, the bind works perfect, i've tested it several ways, and i i create a button it grows the number, but if i use the setInterval function i get an error: Access of undefined property myInt. Why? What does cause this? Please explain it, so I can avoid errors like this. Thanks

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• How to change the value of progressbar in C#?

  - by shekhar

  Hi, I want to add an progress bar into my C# based application. I would like to know what is the good way of updating its value at particular events? My problem is, I have single function in UI which does all the processing.This function in turn calls many more functions, creates objects, updates database, etc. (basically performs all the work) and returns values in an output file. I have access to that function only. So in this how to update the progressbar's value at the end of each step? What is the best practice for this kind of situation? What is the good way to keep UI logic and business logic seperate? I want to avoid writting progressbar related code in my library code. Please suggest some solution. Thanks and Regards,

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• Proper use of of typedef in C++

  - by dicroce

  I have coworkers who occasionally use typedef to avoid typing. For example: typedef std::list<Foobar> FoobarList; ... FoobarList GetFoobars(); Personally, I always hate coming across code like this, largely because it forces me to go lookup the typedef so I can tell how to use it. I also feel like this sort of thing is a potential slippery slope... If you do this, why aren't you doing it more? (pretty soon, your code is totally obfuscated). I found this SO question regarding this issue: when should I use typedef in C I have two questions: 1) am I truly alone in disliking this? 2) If the vast majority of people think this sort of typedef use is OK, what criteria do you use to determine whether to typedef a type?

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• Activity.findViewById returning null sporadically

  - by adstro

  From the crash logs that I am getting from the Android market, I can see that some of my users are getting Force Closes caused by NullPointerExceptions when my code tries to access views that are in my application. In one example, my activity makes a call to findViewById() in onCreate() after I call setContentView(). I get an NPE when I try to access the view after the call to findViewById() (still in onCreate). What has me really scratching my head is that this does not happen all of the time (in fact most of the time the code acts as I would expect), but enough to have me concerned. I could add code to always check for null and avoid the NPE, but I would like to understand what could be causing the sporadic behavior. Does anyone know what could be causing this?

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• Zend disableLayout() leaves html & body tags in output

  - by sunwukung

  Hi all, could anyone take a look at this for me? Problem: trying to output a csv on demand using Zend Framework. I want to avoid creating files on the system so I'm trying to use the same solution posted here: http://stackoverflow.com/questions/1136264/export-csv-in-zend-framework However - I'm still getting html and body tags in the csv. I'm setting layouts in the ini file. I've tried putting the csv call earlier in the request cycle using preDispatch etc - but to no avail. Any help is greatly appreciated SWK

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• Detect NativeDragDrop to Trash or RecycleBin

  - by colder

  I will let user remove item from List with a cool method. Drag an item in adobe air List control and then drop it to Trash(OSX) or Recycle Bin(Win). The trash accept move drag action only. So I think I must set dragMoveEnable=true. When I drag an item to Recycle Bin on Windows. It show accept effect(alpha mask) and Air remove that object from List's dataProvider. So I can find which one is disappear. But when I drag to Trash on MacOSX. It show effect too. But Air do nothing for List. Maybe this is a bug. How can I avoid it? Are there any way to detect where dropped by user?

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• Is it always bad idea to use inline css for used-once property?

  - by user93422

  I have a table, with 10 columns. I want to control the width of each column. Each column is unique, right now I create an external CSS style for each column: div#my-page table#members th.name-col { width: 40px; } I know there is a best practice to avoid inline style. I do approve using external CSS for anything look'n'feel related: fonts, colors, images. But is it really better to use external CSS in this case? It does not incur extra maintenance cost. It is easier to produce. Cons I can think of: If you have separate designers and development team - using inline styles will force designers to modify content-file (aspx in my case). It might use more bandwidth. Anything else I've missed?

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• How can I double-enhance a class with cglib?

  - by artemb

  Hi there! Here's the code: Patient patient = factory.createPatient(); Enhancer enhancer = new Enhancer(); enhancer.setSuperclass(patient.getClass()); enhancer.setCallback(new DefaultMethodInterceptor(patient)); patient = (Patient) enhancer.create(); assertThat(patient.getFirstName()).isNotNull(); Enhancer enhancer2 = new Enhancer(); enhancer2.setSuperclass(patient.getClass()); enhancer2.setCallback(new DefaultMethodInterceptor(patient)); patient = (Patient) enhancer2.create(); assertThat(patient.getFirstName()).isNotNull(); It fails on the last assert with net.sf.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null ... Caused by: java.lang.reflect.InvocationTargetException ... Caused by: java.lang.ClassFormatError: Duplicate method name&signature in class file my/package/entity/Patient$$EnhancerByCGLIB$$ca1e6685$$EnhancerByCGLIB$$f52743be I ask this because I want to enhance Hibernate's entities, but sometimes it returns already enhanced ones by itself and my second enhancement fails. How can I avoid this?

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• Singleton wrapper for Context

  - by kpdvx

  I'm considering creating a singleton wrapper for a Context so my model objects, if necessary, can open and read from a database connection. My model objects do not have access to a Context, and I'd like to avoid needing to pass a reference to a Context from object to object. I was planning to place into this singleton a reference to the Context returned by Application.getApplicationContext(). This singleton object would be initialized in my custom Application instance before anything else would need to or have a chance to use it. Can anyone think of a reason to not do this?

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• populate a treeview with xml file using c#

  - by syedsaleemss

  Im using c#.net windows form application. I have an xml file that contains nodes. I need to populate a treeview with the nodes present in the xml file. Also avoid repeated node names. For this my idea is while populating the treeview, copy the node names into a list and there see if the node already exits. If it already exits, go to the next node else display it. List listOfNodes = new List(); listOfNodes.Add(xNode.Name.ToString()); //if (!(listOfNodes.Contains(xNode.Name.ToString()))) I was trying with this. but Im unable to do. Please suggest me with a proper code.

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• jQuery resize event for div children

  - by Frank Michael Kraft

  $("div.content-left > *, div.content-main > *" ).live('resize',function(){alert("Size changed")}); does not work, because the resize event only applies to window resizes. But in my case the divs change size late, because the content is loaded late by an ajax request - or by clicking a panel menu. I definatley need to avoid to register on all individual events of the children (ajax, click), because that can be very many different events and then it is not maintainable.

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• Divide people into teams for most satisfaction

  - by Jweede

  Just a curiosity question. Remember when in class groupwork the professor would divide people up into groups of a certain number (n)? Some of my professors would take a list of n people one wants to work with and n people one doesn't want to work with from each student, and then magically turn out groups of n where students would be matched up with people they prefer and avoid working with people they don't prefer. To me this algorithm sounds a lot like a Knapsack problem, but I thought I would ask around about what your approach to this sort of problem would be.

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• How to relate keywords to records - Many to Many

  - by webworm

  Hi All, I am looking for suggestions on database design for a sample jobs listing application. I have many jobs that I would like to associate various keywords with. Each job can have multiple keywords. I would like to store the keywords in a seperate table instead of in a field within the Job table so as to avoid mispellings in keywords. What is the best way to relate keywords to the jobs? I was thinking of using an intermediary table that would have a many to many relationship linking keywords to jobs. Is this the best way to go or should I just have a field in the Job table that contains multiple keywords? Thanks for any suggestions.

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• How to get at TCP RTT on Windows (Linux TCP_INFO) as an user

  - by FredAlkin

  I am porting a streaming TCP app from Linux to Windows. The app streams real-time audio data using a preexisting TCP protocol (so switching to UDP isn't an option). Further, I wish to avoid being "part of the problem" and requiring Administrator rights. The Linux code uses getsockopt(... ,SOL_TCP, TCP_INFO, ..) to get the RTT (round trip time) information from the TCP connection. The application level uses this to throttle the amount of data sent over the connection (apparently to balance quality with latency). Is there an equivalent to TCP_INFO on WIndows? (google tells me that Win2K and later supports "TCP Timestamps" which would provide this information, but I've yet to find a way to get at it. Thanks in advance.

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