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  • How to enumerate returned rows in SQL?

    - by SilentGhost
    I was wondering if it would be possible to enumerate returned rows. Not according to any column content but just yielding a sequential integer index. E.g. select ?, count(*) as usercount from users group by age would return something along the lines: 1 12 2 78 3 4 4 42

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  • Ruby getting the diagonal elements in a 2d Array

    - by Calm Storm
    Hi, I was trying some problems with my 2D ruby array and my LOC reduces a lot when I do array slicing. So for example, require "test/unit" class LibraryTest < Test::Unit::TestCase def test_box array = [[1,2,3,4],[3,4,5,6], [5,6,7,8], [2,3,4,5]] puts array[1][2..3] # 5, 6 puts array[1..2][1] # 5, 6, 7, 8 end end I want to know if there is a way to get a diagonal slice? Lets say I want to start at [0,0] and want a diagonal slice of 3. Then I would get elements from [0,0], [1,1], [2,2] and I will get an array like [1,4,7] for example above. Is there any magic one-liner ruby code that can achieve this? 3.times do {some magic stuff?}

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  • Processor, OS : 32bit, 64 bit

    - by Sandbox
    I am new to programming and come from a non-CS background (no formal degree). I mostly program winforms using C#. I am confused about 32 bit and 64 bit.... I mean, have heard about 32 bit OS, 32 bit processor and based on which a program can have maximum memory. How it affects the speed of a program. There are lot more questions which keep coming to mind. I tried to go through some Computer Organization and Architecture books. But, either I am too dumb to understand what is written in there or the writers assume that the reader has some CS background. Can someone explain me these things in a plain simple English or point me to something which does that. EDIT: I have read things like In 32-bit mode, they can access up to 4GB memory; in 64-bit mode, they can access much much more....I want to know WHY to all such things. BOUNTY: Answers below are really good....esp one by Martin. But, I am looking at a thorough explanation, but in plain simple English.

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  • Importing data from a text file using python

    - by Will
    I have a text file containing data in rows and columns (~17000 rows in total). Each column is a uniform number of characters long, with the 'unused' characters filled in by spaces. For example, the first column is 11 characters long, but the last four characters in that column are always spaces (so that it appears to be a nice column when viewed with a text editor). Sometimes it's more than four if the entry is less than 7 characters. The columns are not otherwise separated by commas, tabs, or spaces. They are also not all the same number of characters (the first two are 11, the next two are 8 and the last one is 5 - but again, some are spaces). What I want to do is import the entires (which are numbers) in the last two columns if the second column contains the string 'OW' somewhere in it. Any help would be greatly appreciated.

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  • Binding a collection to Listbox

    - by Blub
    Hi, I basically started today with WPF, and I'm astounded by how difficult it is to do binding. I have an array of Textboxes, in an ObservableCollection, and just want to bind that in my Listbox, so that they arrange themselves vertically. I have fiddled around with this for 3 already, can you help? I'm working in a Wpf "UserControl", not a window as so many tutorials seem to rely on.

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  • C++: Trouble with dependent types in templates

    - by Rosarch
    I'm having trouble with templates and dependent types: namespace Utils { void PrintLine(const string& line, int tabLevel = 0); string getTabs(int tabLevel); template<class result_t, class Predicate> set<result_t> findAll_if(typename set<result_t>::iterator begin, set<result_t>::iterator end, Predicate pred) // warning C4346 { set<result_t> result; return findAll_if_rec(begin, end, pred, result); } } namespace detail { template<class result_t, class Predicate> set<result_t> findAll_if_rec(set<result_t>::iterator begin, set<result_t>::iterator end, Predicate pred, set<result_t> result) { typename set<result_t>::iterator nextResultElem = find_if(begin, end, pred); if (nextResultElem == end) { return result; } result.add(*nextResultElem); return findAll_if_rec(++nextResultElem, end, pred, result); } } Compiler complaints, from the location noted above: warning C4346: 'std::set<result_t>::iterator' : dependent name is not a type. prefix with 'typename' to indicate a type error C2061: syntax error : identifier 'iterator' What am I doing wrong?

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  • Several modules in a package importing one common module

    - by morpheous
    I am writing a python package. I am using the concept of plugins - where each plugin is a specialization of a Worker class. Each plugin is written as a module (script?) and spawned in a separate process. Because of the base commonality between the plugins (e.g. all extend a base class 'Worker'), The plugin module generally looks like this: import commonfuncs def do_work(data): # do customised work for the plugin print 'child1 does work with %s' % data In C/C++, we have include guards, which prevent a header from being included more than once. Do I need something like that in Python, and if yes, how may I make sure that commonfuncs is not 'included' more than once?

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  • Does the OS make a significant difference for Ruby Development ?

    - by Bragaadeesh
    Hi, I have been working in Java for the past 4 years and I am currently switching over to Ruby. I am so excited about it and I feel good to finally get a hands on experience on a scripting language first time. The task assigned to me is to first pick a OS of my choice and setup a Ruby in it and study for 2 weeks. I have been developing applications in windows and Linux is not my cup of tea. Some part of me wants to try out Linux but I want to first convince myself whether OS really matters for Ruby development. If Linux does matter, which distribution can I start looking at? Please advise.

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  • How to iterate over function arguments

    - by Jack
    I have a Python function accepting several string arguments def foo(a, b, c): and concatenating them in a string. I want to iterate over all function arguments to check they are not None. How it can be done? Is there a quick way to convert None to ""? Thanks.

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  • How to use the php fopen() correctly

    - by Jacksta
    I am learning php, trying to use the fopen() function. The php file I am coding is in this directory /domains/xxxxx.com.au/public_html/phpfile.php What path do I specify for the file to be opened, the example I am looking at is based on a server on a pc where this is the file path $filename = "c:/newfile.txt"; not an online server.

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  • Zsh: how to see all buffers?

    - by HH
    You can push things to buffer with ^Q and pop them with ESC-g. Alt+x vi-set-buffer changes buffer somehow. How can I see all the buffers? They are probably some files to look at.

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  • Worst aspect of Python for a newbie

    - by schickb
    I'm wondering specifically what experienced programmers thought when they started developing in Python. I'm sure the answer depends on your background, but my own personal answer is the conversion of basically anything in the language to a True/False value in boolean contexts. Resulting in "oddities" like: if x: not meaning the same thing as: if x == True: I understand why, but it bugs me, and I certainly had to think about it a bit when I first ran into it.

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  • Getter/Setter Problem in Java?

    - by Praveen Chandrasekaran
    Hi Folks, I want to pass the String value between the classes both are same package. so i created the the classs like the code: public class Map_Delegate { String myLatitude; String myLongitude; String myName; private String TAG = "Map_Delegate"; public String getMyName() { return this.myName; } public void setMyName(String value) { Log.v(TAG, value); this.myName = value; } public String getMyLatitude() { return this.myLatitude; } public void setMyLatitude(String value) { Log.v(TAG, value); this.myLatitude = value; } public String getMyLongitude() { return this.myLongitude; } public void setMyLongitude(String value) { Log.v(TAG, value); this.myLongitude = value; } } But it can't pass the value. I done like this code to set the value: Map_Delegate map = new Map_Delegate(); map.setMyName(first_name_temp + " " + last_name_temp); map.setMyLatitude(homeLatitude_temp); map.setMyLongitude(homeLongitude_temp); code to get the value: Map_Delegate map = new Map_Delegate(); name_val = getMyName(); lat_val = getMyLatitude(); long_val = getMyLongitude(); Why get the Null value can you Guess? All classes in the same package and public .AnyIdea?

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  • What's a good starting point, tutorial, or project, to learn database programming?

    - by DarthNoodles
    I've been a Software Developer now for over 10 years. I've mostly worked in Embedded C with some time spent on C++ (limited) and Java. I'm looking to learn some new technologies and skills. I thought that database programming may be interesting to learn. I would like to make my own pet project in order to learn these things. My platform of choice is Windows but can work in Linux also. My ideal pet project would involve a GUI and some network/internet programming also which I have some experience doing. I wouldn't mind getting into C# but don't want to bite off more than I can chew right now as my spare time is limited. If I understand correctly SQLite allows for programs to use a database without running an ODBC server. Is this correct? Is that a good place to start? What can I do to start that is not too complicated but not so simple that I won't learn the details also? Your opinions and feedback would be appreciated.

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  • .htaccess: RewriteCond syntax?

    - by Rosarch
    I'm using Drupal 6. Typically, when the user requests a URL for which Drupal has no response, it uses index.php as the error document. However, I'd like to suspend this behavior for a specific URL. How can I do this? RewriteCond %{REQUEST_FILENAME} !=fail RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_URI} !=/favicon.ico RewriteRule ^(.*)$ index.php?q=$1 [L,QSA] Where "fail" is the path I want to block. So www.example.com/fail should result in a 404. Incidentally, what does [L, QSA] do? I've looked at documentation without luck.

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  • Normal C++ code in Qt doesnt build and run

    - by Nick
    Hello. I am using Qt under linux, if it matters. I ran successfully under Geany (a simple c++ compiler) the following: //my first program in C++ Hello World! include using namespace std; int main () {cout << "Hello World!"; return 0;} I opened Qt source file and copied the exact same code and i can't build or run. Thank you for your responses to this simple problem.

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  • Python to extract data from a file

    - by user297003
    Hi, I am new to python. I am trying to extract the text between that has specific text file: ---- data1 data1 data1 extractme ---- data2 data2 data2 ---- data3 data3 extractme ---- and then dump it to text file so that ---- data1 data1 data1 extractme --- data3 data3 extractme --- Thanks for the help.

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  • I need help to automate my concatenate to change daily without having to manually input the new data

    - by Harold Nottingham
    Hi there I use concatenate to pull data together from different cells in my spreadsheet. Since my data changes daily, I want the formula to also change daily without having to manually input the new cell in the concatenate formula. I am looking for a way to do this but not sure how. Can anyone out there help me out please!? I appreciate the assistance in advance!

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  • (newbie) type signature "Maybe a" doesn't like "Just [Event]"

    - by sisif
    i'm still learning Haskell and need help with the type inference please! using packages SDL and Yampa i get the following type signature from FRP.Yampa.reactimate: (Bool -> IO (DTime, Maybe a)) and i want to use it for: myInput :: Bool -> IO (DTime, Maybe [SDL.Event]) myInput isBlocking = do event <- SDL.pollEvent return (1, Just [event]) ... reactimate myInit myInput myOutput mySF but it says Couldn't match expected type `()' against inferred type `[SDL.Event]' Expected type: IO (DTime, Maybe ()) Inferred type: IO (DTime, Maybe [SDL.Event]) In the second argument of `reactimate', namely `input' In the expression: reactimate initialize input output process i thought "Maybe a" allows me to use anything, even a SDL.Event list? why is it expecting "Maybe ()" when the type signature is actually "Maybe a"? why does it want an empty tuple, or a function taking no arguments, or what is () supposed to be?

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  • DB fields not showing up in association custom queries?

    - by Kevin
    I have a notification list that the user can select different show options for different kinds of notifications along with how many results are returned. I'm keeping them in the user model because I want the custom sort to stay with the user between sessions. Here is the association in my user model: has_many :notifications, :class_name => "Notification", :foreign_key => "user_id", :conditions => ["won = ? and lost = ? and paid = ?", self.prefs_won, self.prefs_lost, self.prefs_paid], :limit => self.prefs_results.to_s But when I use the above code, Rails throws me an "unknown method" error for self.prefs_won. It is definitely a field in my database and set as a boolean value, but Rails can't find it... what's the problem?

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  • Checking for length of ul and removing an li element

    - by Legend
    I am trying to remove the last <li> element from a <ul> element only if it exceeds a particular length. For this, I am doing something like this: var selector = "#ulelement" if($(selector).children().length > threshold) { $(selector + " >:last").remove(); } I don't like the fact that I have to use the selector twice. Is there a shorter way to do this? Something like a "remove-if-length-greater-than-threshold" idea. I was thinking that maybe there is a way to do this using the live() function but I have no idea how.

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  • Random Loss of precision in Python ReadLine()

    - by jackyouldon
    Hi all, We have a process which takes a very large csv (1.6GB) and breaks it down into pieces (in this case 3). This runs nightly and normally doesn't give us any problems. When it ran last night, however, the first of the output files had lost precision on the numeric fields in the data. The active ingredient in the script are the lines: while lineCounter <= chunk: oOutFile.write(oInFile.readline()) lineCounter = lineCounter + 1 and the normal output might be something like StringField1; StringField2; StringField3; StringField4; 1000000; StringField5; 0.000054454 etc. On this one occasion and in this one output file the numeric fields were all output with 6 zeros at the end i.e. StringField1; StringField2; StringField3; StringField4; 1000000.000000; StringField5; 0.000000 We are using Python v2.6 (and don't want to upgrade unless we really have to) but we can't afford to lose this data. Does anyone have any idea why this might have happened? If the readline is doing some kind of implicit conversion is there a way to do a binary read, because we really just want this data to pass through untouched? It is very wierd to us that this only affected one of the output files generated by the same script, and when it was rerun the output was as expected. thanks Jack

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