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• How to have localized style when writing cell with xlwt

  - by lfagundes

  I'm writing an Excel spreadsheet with Python's xlwt and I need numbers to be formatted using "." as thousands separator, as it is in brazilian portuguese language. I have tried: style.num_format_str = r'#,##0' And it sets the thousands separator as ','. If I try setting num_format_str to '#.##0', I'll get number formatted as 1234.000 instead of 1.234. And if I open document in OpenOffice and format cells, I can set the language of the cell to "Portuguese (Brazil)" and then OpenOffice will show the format code as being "#.##0", but I don't find a way to set the cell's language to brazilian portuguese. Any ideas?

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• Unique identifiers for users

  - by Christopher McCann

  If I have a table of a hundred users normally I would just set up an auto-increment userID column as the primary key. But if suddenly we have a million users or 5 million users then that becomes really difficult because I would want to start becoming more distributed in which case an auto-increment primary key would be useless as each node would be creating the same primary keys. Is the solution to this to use natural primary keys? I am having a real hard time thinking of a natural primary key for this bunch of users. The problem is they are all young people so they do not have national insurance numbers or any other unique identifier I can think of. I could create a multi-column primary key but there is still a chance, however miniscule of duplicates occurring. Does anyone know of a solution? Thanks

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• WPF ListView.CurrentChanged too fast for binding

  - by matt

  My case: MVVM ListView+Details(custom UserControl) List bound to MV.Items (IsSynchronizedWithCurrent=true) Details bound to MV.Items.Current MV.Items.Count == 100 about 0.2sec to read details (lazy mode) When I hold the down arrow on the list, very strange things happen: list items order change current changes in the random order CPU usage drastically increments and eventually all hangs. I've read some post that one should start the timer or run handler in the background, but I am not able to do that, since all the binding WPF does for me. Is there some way to instruct the binding in my DetailsControl, to wait a while before accepting CurrentItem? Or should I just resign from the clean solution and write custom code in my MV to handle that?

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• prevent multiple login with same login credentials in php

  - by shinod

  My website has premium videos, for which users have to pay to watch it. I am sending a random user name and password to the user's email id when the payment is completed. Then I want to assure no more than one user use that login credentials simultaneously. For that I use a login_status column in database table with login credentials and change it to 1 when one user login and change to 0 when user log out. But the problem is, if the user close browser or network connection loss may happened will not update database. Then login_will be 1 undefinitely and no one can use that login credentials again. Is there any idea to accomplish my task?

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• Cache consistency & spawning a thread

  - by Dave Keck

  Background I've been reading through various books and articles to learn about processor caches, cache consistency, and memory barriers in the context of concurrent execution. So far though, I have been unable to determine whether a common coding practice of mine is safe in the strictest sense. Assumptions The following pseudo-code is executed on a two-processor machine: int sharedVar = 0; myThread() { print(sharedVar); } main() { sharedVar = 1; spawnThread(myThread); sleep(-1); } main() executes on processor 1 (P1), while myThread() executes on P2. Initially, sharedVar exists in the caches of both P1 and P2 with the initial value of 0 (due to some "warm-up code" that isn't shown above.) Question Strictly speaking – preferably without assuming any particular CPU – is myThread() guaranteed to print 1? With my newfound knowledge of processor caches, it seems entirely possible that at the time of the print() statement, P2 may not have received the invalidation request for sharedVar caused by P1's assignment in main(). Therefore, it seems possible that myThread() could print 0. References These are the related articles and books I've been reading. (It wouldn't allow me to format these as links because I'm a new user - sorry.) Shared Memory Consistency Models: A Tutorial hpl.hp.com/techreports/Compaq-DEC/WRL-95-7.pdf Memory Barriers: a Hardware View for Software Hackers rdrop.com/users/paulmck/scalability/paper/whymb.2009.04.05a.pdf Linux Kernel Memory Barriers kernel.org/doc/Documentation/memory-barriers.txt Computer Architecture: A Quantitative Approach amazon.com/Computer-Architecture-Quantitative-Approach-4th/dp/0123704901/ref=dp_ob_title_bk

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• C - floating point rounding

  - by hatorade

  I'm trying to understand how floating point numbers work. I think I'd like to test out what I know / need to learn by evaluating the following: I would like to find the smallest x such that x + 1 = x, where x is a floating point number. As I understand it, this would happen in the case where x is large enough so that x + 1 is closer to x than the next number higher than x representable by floating point. So intuitively it seems it would be the case where I don't have enough digits in the significand. Would this number x then be the number where the significand is all 1's. But then I can't seem to figure out what the exponent would have to be. Obviously it would have to be big (relative to 10^0, anyway).

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• Reading numeric Excel data as text using xlrd in Python

  - by Brian

  Hi guys, I am trying to read in an Excel file using xlrd, and I am wondering if there is a way to ignore the cell formatting used in Excel file, and just import all data as text? Here is the code I am using for far: import xlrd xls_file = 'xltest.xls' xls_workbook = xlrd.open_workbook(xls_file) xls_sheet = xls_workbook.sheet_by_index(0) raw_data = [['']*xls_sheet.ncols for _ in range(xls_sheet.nrows)] raw_str = '' feild_delim = ',' text_delim = '"' for rnum in range(xls_sheet.nrows): for cnum in range(xls_sheet.ncols): raw_data[rnum][cnum] = str(xls_sheet.cell(rnum,cnum).value) for rnum in range(len(raw_data)): for cnum in range(len(raw_data[rnum])): if (cnum == len(raw_data[rnum]) - 1): feild_delim = '\n' else: feild_delim = ',' raw_str += text_delim + raw_data[rnum][cnum] + text_delim + feild_delim final_csv = open('FINAL.csv', 'w') final_csv.write(raw_str) final_csv.close() This code is functional, but there are certain fields, such as a zip code, that are imported as numbers, so they have the decimal zero suffix. For example, is there is a zip code of '79854' in the Excel file, it will be imported as '79854.0'. I have tried finding a solution in this xlrd spec, but was unsuccessful.

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• Do I need to use decimal places when using floats? Is the "f" suffix necessary?

  - by Paulo Fierro

  I've seen several examples in books and around the web where they sometimes use decimal places when declaring float values even if they are whole numbers, and sometimes using an "f" suffix. Is this necessary? For example: [UIColor colorWithRed:0.8 green:0.914 blue:0.9 alpha:1.00]; How is this different from: [UIColor colorWithRed:0.8f green:0.914f blue:0.9f alpha:1.00f]; Does the trailing "f" mean anything special? Getting rid of the trailing zeros for the alpha value works too, so it becomes: [UIColor colorWithRed:0.8 green:0.914 blue:0.9 alpha:1]; So are the decimal zeros just there to remind myself and others that the value is a float? Just one of those things that has puzzled me so any clarification is welcome :)

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• How to code Fizzbuzz in F#

  - by Russell

  I am currently learning F# and have tried (an extremely) simple example of FizzBuzz. This is my initial attempt: for x in 1..100 do if x % 3 = 0 && x % 5 = 0 then printfn "FizzBuzz" elif x % 3 = 0 then printfn "Fizz" elif x % 5 = 0 then printfn "Buzz" else printfn "%d" x What solutions could be more elegant/simple/better (explaining why) using F# to solve this problem? Note: The FizzBuzz problem is going through the numbers 1 to 100 and every multiple of 3 prints Fizz, every multiple of 5 prints Buzz, every multiple of both 3 AND 5 prints FizzBuzz. Otherwise, simple the number is displayed. Thanks :)

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• Embedding a YouTube Video Based on a PHP Variable

  - by jeffpm

  I have a website that I am creating for a class project. The website shows information about bands (which is stored in a mysql database). I am trying to spruce up the site a bit, and I would like to embed a YouTube video based on the band's name. Say, for instance, I have "Led Zeppelin" stored in my database. How can I take a PHP variable containing "Led Zeppelin", search YouTube using that variable, find a random video, and then embed that in the website? From the research I've done, it seems you can only embed YouTube videos if you know the exact address of the video. Thanks!

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• math syntax checker written in python

  - by neurino

  All I need is to check, using python, if a string is a valid math expression or not. For simplicity let's say I just need + - * / operators (+ - as unary too) with numbers and nested parenthesis. I add also simple variable names for completeness. So I can test this way: test("-3 * (2 + 1)") #valid test("-3 * ") #NOT valid test("v1 + v2") #valid test("v2 - 2v") #NOT valid ("2v" not a valid variable name) I tried pyparsing but just trying the example: "simple algebraic expression parser, that performs +,-,*,/ and ^ arithmetic operations" I get passed invalid code and also trying to fix it I always get wrong syntaxes being parsed without raising Exceptions just try: >>>test('9', 9) 9 qwerty = 9.0 ['9'] => ['9'] >>>test('9 qwerty', 9) 9 qwerty = 9.0 ['9'] => ['9'] both test pass... o_O Any advice?

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• SQLServer 2008 Pivot

  - by Mitch

  I need to show some information in a graph, the data is held in a SQL Server 2008 table. The graph is expecting 2 columns, one for QuestionNumber and the other for Score. The table containing the data has column names that correspond to the question numbers ie A1, A2, A3, A4, B1, B2, B3, B4, C1, C2. Each question is given a score of 1 to 5. I need to show a graph where the X axis shows A1, A2, A3 etc and the Y axis shows the score. I'm thinking I somehow need to rotate the data to achive this, but I'm not sure how. Maybe a different technique can acheive this rather that a Rotate, so I'm open to any ideas.

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• Rails named_scope across multiple tables

  - by wakiki

  I'm trying to tidy up my code by using named_scopes in Rails 2.3.x but where I'm struggling with the has_many :through associations. I'm wondering if I'm putting the scopes in the wrong place... Here's some pseudo code below. The problem is that the :accepted named scope is replicated twice... I could of course call :accepted something different but these are the statuses on the table and it seems wrong to call them something different. Can anyone shed light on whether I'm doing the following correctly or not? I know Rails 3 is out but it's still in beta and it's a big project I'm doing so I can't use it in production yet. class Person < ActiveRecord::Base has_many :connections has_many :contacts, :through => :connections named_scope :accepted, :conditions => ["connections.status = ?", Connection::ACCEPTED] # the :accepted named_scope is duplicated named_scope :accepted, :conditions => ["memberships.status = ?", Membership::ACCEPTED] end class Group < ActiveRecord::Base has_many :memberships has_many :members, :through => :memberships end class Connection < ActiveRecord::Base belongs_to :person belongs_to :contact, :class_name => "Person", :foreign_key => "contact_id" end class Membership < ActiveRecord::Base belongs_to :person belongs_to :group end I'm trying to run something like person.contacts.accepted and group.members.accepted which are two different things. Shouldn't the named_scopes be in the Membership and Connection classes? One solution is to just call the two different named scope something different in the Person class or even to create separate associations (ie. has_many :accepted_members and has_many :accepted_contacts) but it seems hackish and in reality I have many more than just accepted (ie. banned members, ignored connections, pending, requested etc etc)

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• Setting a VCProject property to default

  - by Ofek Shilon

  I'm trying some VS2005 IDE macros to modify a large amount of projects (~80) within a solution. Some of the properties I wish to set do expose a programmatic interface to 'default', but many others do not. Is there a generic way to set such properties to their default? (eventually meaning erasing them from the .vcproj file) Simplified example, setting some random properties: Sub SetSomeProps() Dim prj As VCProject Dim cfg As VCConfiguration Dim toolCompiler As VCCLCompilerTool Dim toolLinker As VCLinkerTool Dim EnvPrj As EnvDTE.Project For Each EnvPrj In DTE.Solution.Projects prj = EnvPrj.Object cfg = prj.Configurations.Item(1) toolLinker = cfg.Tools("VCLinkerTool") If toolLinker IsNot Nothing Then ' Some tool props that expose a *default* interface' toolLinker.EnableCOMDATFolding = optFoldingType.optFoldingDefault toolLinker.OptimizeReferences = optRefType.optReferencesDefault toolLinker.OptimizeForWindows98 = optWin98Type.optWin98Default End If toolCompiler = cfg.Tools("VCCLCompilerTool") If toolCompiler IsNot Nothing Then ' How to set it to default? (*erase* the property from the .vcproj)' toolCompiler.CallingConvention = callingConventionOption.callConventionCDecl toolCompiler.WholeProgramOptimization = False toolCompiler.Detect64BitPortabilityProblems = False End If Next End Sub Any advice would be appreciated.

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• Validate a string in a table in SQL Server

  - by Ashish Gupta

  I need to check If a column value (string) in SQL server table starts with a small letter and can only contain '_', '-', numbers and alphabets. I know I can use a SQL server CLR function for that. However, I am trying to implement that validation using a scalar UDF and could make very little here...I can use 'NOT LIKE', but I am not sure how to make sure I validate the string irrespective of the order of characters or in other words write a pattern in SQL for this. Am I better off using a SQL CLR function? Any help will be appreciated.. Thanks in advance

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• Where to find great proxy servers for testing GeoIP services?

  - by Andreas

  We would like to test a GeoIP-Service. Therefore we need to go to the site with an IP from another country. There are a lot of free proxy lists like http://nntime.com/proxy-country/ The problem with them is, that only the CoDeen-Proxies are working. But with CoDeen you can't select your country of origin (the same as with TOR). You get redirected to a random proxy in the network. Where to find good proxy server for testing the GeoIP Services? Free proxy servers would be great, but if they cost something small that doesn't matter.

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• Detecting that the stack is full in C/C++

  - by Martin Kristiansen

  When writing C++ code I've learned that using the stack to store memory is a good idea. But recently I ran into a problem: I had an experiment that had code that looked like this: void fun(unsigned int N) { float data_1[N*N]; float data_2[N*N]; /* Do magic */ } The code exploted with a seqmentation fault at random, and I had no idea why. It turned out that problem was that I was trying to store things that were to big on my stack, is there a way of detecting this? Or at least detecting that it has gone wrong?

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• Python Mersenne Twister implementation

  - by B Rivera

  I have Python 3.1.2 and I'm using Windows XP. Where can I see Python's implementation of the Mersenne Twister? In the Python docs it is stated that the Mersenne Twister was written in C and the Python History and License ( http://docs.python.org/py3k/license.html?highlight=mersenne%20twister ) states that "The _random module includes code based on a download from http://www.math.keio.ac.jp/matumoto/MT2002/emt19937ar.html." random.py imports _random which apparently has the Mersenne Twister implementation in it. I can't seem to locate _random. Any thoughts?

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• Memory footprint of a parsed XML file in Classic ASP?

  - by Pete Duncanson

  Anyone know of a way to find out the amount of memory/size of a XMLDocument once it has parsed a XML file? I've been doing "beer mat" calculations so far but have been asked to come up with some more legit numbers through monitoring some how. I need to create about 1500 XML files (via FreeThreadedXMl-DOM object), which verge between 3-9K in size and store them in Application vars but our SysAdmin is worried about us gobbling up too much memory. Other than the crude method of booting up a fresh IIS instance and then loading everything in and monitoring before and after memory usage in Task Manager I can't think of a way of doing it with a bit more accuracy.

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• loops and conditionals inside triggers

  - by Ying

  I have this piece of logic I would like to implement as a trigger, but I have no idea how to do it! I want to create a trigger that, when a row is deleted, it checks to see if the value of one of its columns exists in another table, and if it does, it should also perform a delete on another table based on another column. So say we had a table Foo that has columns Bar, Baz. This is what id be doing if i did not use a trigger: function deleteFromFooTable(FooId) { SELECT (Bar,Baz) FROM FooTable WHERE id=FooId if not-empty(SELECT * FROM BazTable WHERE id=BazId) DELETE FROM BarTable WHERE id=BarId DELETE FROM FooTable WHERE id=FooId } I jumped some hoops in that pseudo code, but i hope you all get where im going. It seems what i would need is a way to do conditionals and to loop(in case of multiple row deletes?) in the trigger statement. So far, I haven't been able to find anything. Is this not possible, or is this bad practice? Thanks!

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• How do I get the name of the newest file via the Terminal?

  - by Alec

  I'm trying to create a macro for Keyboard Maestro for OS X doing the following: Get name of newest file in a directory on my disk based on date created; Paste the text "newest file: " plus the name of the newest file. One of its options is to "Execute a shell script", so I thought that would do it for 1. After Googling around a bit I came up with this: cd /path/to/directory/ ls -t | head -n1 This sorts it right, and returns the first filename. However, it also seems to includes a line break, which I do not want. As for 2: I can output the text "newest file: " with a different action in the app, and paste the filename behind that. But I'm wondering if you can't return "random text" + the outcome of the ls command. So my question is: can I do this only using the ls command? And how do I get just the name of the latest file without any linebreaks or returns?

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• Dependency between operations in scala actors

  - by paradigmatic

  I am trying to parallelise a code using scala actors. That is my first real code with actors, but I have some experience with Java Mulithreading and MPI in C. However I am completely lost. The workflow I want to realise is a circular pipeline and can be described as the following: Each worker actor has a reference to another one, thus forming a circle There is a coordinator actor which can trigger a computation by sending a StartWork() message When a worker receives a StartWork() message, it process some stuff locally and sends DoWork(...) message to its neighbour in the circle. The neighbours do some other stuff and sends in turn a DoWork(...) message to its own neighbour. This continues until the initial worker receives a DoWork() message. The coordinator can send a GetResult() message to the initial worker and wait for a reply. The point is that the coordinator should only receive a result when data is ready. How can a worker wait that the job returned to it before answering the GetResult() message ? To speed up computation, any worker can receive a StartWork() at any time. Here is my first try pseudo-implementation of the worker: class Worker( neighbor: Worker, numWorkers: Int ) { var ready = Foo() def act() { case StartWork() => { val someData = doStuff() neighbor ! DoWork( someData, numWorkers-1 ) } case DoWork( resultData, remaining ) => if( remaining == 0 ) { ready = resultData } else { val someOtherData = doOtherStuff( resultData ) neighbor ! DoWork( someOtherData, remaining-1 ) } case GetResult() => reply( ready ) } } On the coordinator side: worker ! StartWork() val result = worker !? GetResult() // should wait

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• Monotone-increasing Version Number based on Mercurial Commits

  - by Isaac

  When I was using subversion for the code for an application, I could append a period and the result of svnversion to the version number to create a unique and monotone-increasing version number and also be guaranteed that any check-out of the same revision of the code would generate the same version number. In Mercurial, because revision numbers are not necessarily consistent across clones, the local revision number is not suitable. The hash is appropriately unique and consistent, but does not create a number that is monotone-increasing. How can I generate a suitable number to append to the version number based on the Mercurial repository commits?

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• Easiest way to pass a javascript array or its values to a servlet and convert to a HashMap

  - by Ankur

  I have a Javascript array. I want to pass it's data to a servlet using the ajax() method of jQuery. What is the easiest way to do this. The index values i.e. the i in array[i] are not in order, they are numbers that have meaning themselves, hence I cannot simply loop through and create a GET queryString, or so I believe. Maybe I should be converting the JavaScript array to a JSON Object and sending that to the server ?? I am stumped on this one.

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• Truncate a HTML formatted text.

  - by marharépa

  Hi there! I've got a variable which is formatted with random HTML code. I call it to {$text} and i truncate it. The value is for example: <div>Lorem <i>ipsum <b>dolor <span>sit </span>amet</b>, con</i> elit.</div> If i truncate the text's first ~30 letters, I'll get this: <div>Lorem <i>ipsum <b>dolor <span>sit The problem is, I can't close the elements. So, I need a script, which check the <*> elements in the code (where * could be anything), and if it dont have a close tag, close 'em. Please help me in this. Thanks.

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