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• php: fopen() of an URL breaks for domain names, not for numerical addresses

  - by b0fh

  After hours of trying to debug a third-party application having trouble with fopen(), i finally discovered that php -r 'echo(file_get_contents("http://www.google.com/robots.txt"));' fails, but php -r 'echo(file_get_contents("http://173.194.32.81/robots.txt"));' Succeeds. Note that as the webserver user, I can ping www.google.com and it resolves just fine. I straced both executions of PHP, and they diverge like this: For the numerical v4 URL: socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3 fcntl(3, F_GETFL) = 0x2 (flags O_RDWR) fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 connect(3, {sa_family=AF_INET, sin_port=htons(80), sin_addr=inet_addr("173.194 poll([{fd=3, events=POLLOUT}], 1, 0) = 0 (Timeout) ...[bunch of poll/select/recvfrom]... close(3) = 0 For the domain name: socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP) = 3 close(3) = 0 PHP didn't even try to do anything with that socket, it seems. Or even resolve the domain, for that matter. WTF ? Recompiling PHP with or without ipv6 support did not seem to matter. Disabling ipv6 on this system is not desirable. Gentoo Linux, PHP 5.3.14, currently giving a try to PHP 5.4 and see if it helps. Anyone has an idea ? EDIT: php -r 'echo gethostbyname("www.google.com");' Works and yield an ipv4, while php -r 'echo(file_get_contents("http://[2a00:1450:4007:803::1011]/"));' Seems to return a blank result. EDIT 2: I didn't even notice the first time, that the v6 socket opened when the name is used is a SOCK_DGRAM.

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• Bubble Breaker Game Solver better than greedy?

  - by Gregory

  For a mental exercise I decided to try and solve the bubble breaker game found on many cell phones as well as an example here:Bubble Break Game The random (N,M,C) board consists N rows x M columns with C colors The goal is to get the highest score by picking the sequence of bubble groups that ultimately leads to the highest score A bubble group is 2 or more bubbles of the same color that are adjacent to each other in either x or y direction. Diagonals do not count When a group is picked, the bubbles disappear, any holes are filled with bubbles from above first, ie shift down, then any holes are filled by shifting right A bubble group score = n * (n - 1) where n is the number of bubbles in the bubble group The first algorithm is a simple exhaustive recursive algorithm which explores going through the board row by row and column by column picking bubble groups. Once the bubble group is picked, we create a new board and try to solve that board, recursively descending down Some of the ideas I am using include normalized memoization. Once a board is solved we store the board and the best score in a memoization table. I create a prototype in python which shows a (2,15,5) board takes 8859 boards to solve in about 3 seconds. A (3,15,5) board takes 12,384,726 boards in 50 minutes on a server. The solver rate is ~3k-4k boards/sec and gradually decreases as the memoization search takes longer. Memoization table grows to 5,692,482 boards, and hits 6,713,566 times. What other approaches could yield high scores besides the exhaustive search? I don't seen any obvious way to divide and conquer. But trending towards larger and larger bubbles groups seems to be one approach Thanks to David Locke for posting the paper link which talks above a window solver which uses a constant-depth lookahead heuristic.

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• Class Structure w/ LINQ, Partial Classes, and Abstract Classes

  - by Jason

  I am following the Nerd Dinner tutorial as I'm learning ASP.NET MVC, and I am currently on Step 3: Building the Model. One part of this section discusses how to integrate validation and business rule logic with the model classes. All this makes perfect sense. However, in the case of this source code, the author only validates one class: Dinner. What I am wondering is, say I have multiple classes that need validation (Dinner, Guest, etc). It doesn't seem smart to me to repeatedly write these two methods in the partial class: public bool IsValid { get { return (GetRuleViolations().Count() == 0); } } partial void OnValidate(ChangeAction action) { if (!IsValid) { throw new ApplicationException("Rule violations prevent saving."); } } What I'm wondering is, can you create an abstract class (because "GetRuleViolations" needs to be implemented separately) and extend a partial class? I'm thinking something like this (based on his example): public partial class Dinner : Validation { public IEnumerable<RuleViolation> GetRuleViolations() { yield break; } } This doesn't "feel" right, but I wanted to check with SO to get opinions of individuals smarter than me on this. I also tested it out, and it seems that the partial keyword on the OnValidate method is causing problems (understandably so). This doesn't seem possible to fix (but I could very well be wrong). Thanks!

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• Python TypeError: an integer is required

  - by kartiku

  import scipy,array def try_read_file(): def line_reader(lines): for l in lines: i = l.find('#') if i != -1: l = l[:i] l = l.strip() if l: yield l def column_counter(): inputer = (line.split() for line in line_reader(file('/home/kartik/Downloads/yahoo_dataset/set1.train.txt'.strip()))) loopexit = 0 for line in inputer: feature_tokens = (token.split(':') for token in line[6:]) feature_ids = array.array('I') for t in feature_tokens: feature_ids.append(int (t[0])) tmpLength = feature_ids[-1] print feature_ids loopexit = loopexit + 1 if loopexit > 0: break return tmpLength def line_counter(): inputer = (line.split() for line in line_reader(file('/home/kartik/Downloads/yahoo_dataset/set1.train.txt'.strip()))) noOfRows = 0 for line in inputer: noOfRows = noOfRows + 1 return noOfRows inputer = (line.split() for line in line_reader(file('/home/kartik/Downloads/yahoo_dataset/set1.train.txt'.strip()))) feature_id_list = [] feature_value_list = [] relevance_list = [] noOfRows = line_counter() noOfCols = column_counter() print noOfRows print noOfCols # line 52 #Create the feature array feature_array = scipy.zeros((noOfRows,noOfCols), float) rowCounter = 1; for line in inputer: feature_tokens = (token.split(':') for token in line[6:]) feature_ids = array.array('I') feature_values = array.array('f') for t in feature_tokens: feature_ids.append(int(t[0])) if (t[0]!=colCounter): feature_array[rowCounter,colCounter] = 0 else: feature_array[rowCounter,colCounter] = t[1] feature_values.append(float(t[1])) colCounter = colCounter + 1; label = float(line[0]) assert(line[1].startswith('qid:')) query_id = int(line[1][4:]) feature_id_list.append(feature_ids) feature_value_list.append(feature_values) relevance_list.append(label) rowCounter = rowCounter + 1; return feature_array Error: Traceback (most recent call last): File "<pyshell#97>", line 1, in <module> try_read_file() File "/home/kartik/Python/prelim_read.py", line 52, in try_read_file print noOfCols TypeError: an integer is required What is the problem, i couldn't figure it out? I tried to debug it, but it doesnt really go inside those methods. It gives me an address in place of those variables.

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• Can't debug Java Windows Services with jhat, jps, jstack

  - by Matthew McCullough

  I frequently showcase the jhat, jps, and jstack tool set to developers on Linux and Mac. However, a developer recently indicated that these are unusable in Windows if the Java app in question is running as a Windows Service. A Sun-filed bug says something very similar, but was closed due to inactivity. I have tested this out for myself, and indeed it appears true, though I can hardly believe it. Here is the setup: Tomcat or similar running as a Windows service with the "Log On As" == "Local System" A user with Admin privileges logged in to the same Windows machine. Admin opens Windows Task Manager, can see java.exe running Admin opens console, types "jps", gets back a list of processes that does not include Tomcat's java service process. As a brute force attempt, get the PID of tomcat as a service from Windows Task Manager. Type jstack < pid . Get a reply: < pid no such process This appears reproducible under Windows XP, Windows 2003 Server, and Windows 7. Java versions 1.5 and 1.6 yield the same outcome. Is there a way from the terminal, even though logged in as Admin, to "sudo up" to get JPS and the other tools to see the java service?

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• using python 'with' statement with iterators?

  - by Stephen

  Hi, I'm using Python 2.5. I'm trying to use this 'with' statement. from __future__ import with_statement a = [] with open('exampletxt.txt','r') as f: while True: a.append(f.next().strip().split()) print a The contents of 'exampletxt.txt' are simple: a b In this case, I get the error: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/tmp/python-7036sVf.py", line 5, in <module> a.append(f.next().strip().split()) StopIteration And if I replace f.next() with f.read(), it seems to be caught in an infinite loop. I wonder if I have to write a decorator class that accepts the iterator object as an argument, and define an __exit__ method for it? I know it's more pythonic to use a for-loop for iterators, but I wanted to implement a while loop within a generator that's called by a for-loop... something like def g(f): while True: x = f.next() if test1(x): a = x elif test2(x): b = f.next() yield [a,x,b] a = [] with open(filename) as f: for x in g(f): a.append(x)

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• Validation without ServiceLocator

  - by Dmitriy Nagirnyak

  Hi, I am getting back again and again to it thinking about the best way to perform validation on POCO objects that need access to some context (ISession in NH, IRepository for example). The only option I still can see is to use S*ervice Locator*, so my validation would look like: public User : ICanValidate { public User() {} // We need this constructor (so no context known) public virtual string Username { get; set; } public IEnumerable<ValidationError> Validate() { if (ServiceLocator.GetService<IUserRepository>().FindUserByUsername(Username) != null) yield return new ValidationError("Username", "User already exists.") } } I already use Inversion Of control and Dependency Injection and really don't like the ServiceLocator due to number of facts: Harder to maintain implicit dependencies. Harder to test the code. Potential threading issues. Explicit dependency only on the ServiceLocator. The code becomes harder to understand. Need to register the ServiceLocator interfaces during the testing. But on the other side, with plain POCO objects, I do not see any other way of performing the validation like above without ServiceLocator and only using IoC/DI. So the question would be: is there any way to use DI/IoC for the situation described above? Thanks, Dmitriy.

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• Why does VBA Find loop fail when called from Evaluate?

  - by Abiel

  I am having some problems running a find loop inside of a subroutine when the routine is called using the Application.Evaluate or ActiveSheet.Evaluate method. For example, in the code below, I define a subroutine FindSub() which searches the sheet for a string "xxx". The routine CallSub() calls the FindSub() routine using both a standard Call statement and Evaluate. When I run Call FindSub, everything will work as expected: each matching address gets printed out to the immediate window and we get a final message "Finished up" when the code is done. However, when I do Application.Evaluate "FindSub()", only the address of the first match gets printed out, and we never reach the "Finished up" message. In other words, an error is encountered after the Cells.FindNext line as the loop tries to evaluate whether it should continue, and program execution stops without any runtime error being printed. I would expect both Call FindSub and Application.Evaluate "FindSub()" to yield the same results in this case. Can someone explain why they do not, and if possible, a way to fix this? Thanks. Note: In this example I obviously do not need to use Evaluate. This version is simplified to just focus on the particular problem I am having in a more complex situation. Sub CallSub() Call FindSub Application.Evaluate "FindSub()" End Sub Sub FindSub() Dim rngFoundCell As Range Dim rngFirstCell As Range Set rngFoundCell = Cells.Find(What:="xxx", after:=ActiveCell, LookIn:=xlValues, _ LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlNext, _ MatchCase:=False, SearchFormat:=False) If Not rngFoundCell Is Nothing Then Set rngFirstCell = rngFoundCell Do Debug.Print rngFoundCell.Address Set rngFoundCell = Cells.FindNext(after:=rngFoundCell) Loop Until (rngFoundCell Is Nothing) Or (rngFoundCell.Address = rngFirstCell.Address) End If Debug.Print "Finished up" End Sub

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• how to get cartesian products between database and local sequences in linq?

  - by JD

  I saw this similar question here but can't figure out how to use Contains in Cartesian product desired result situation: http://stackoverflow.com/questions/1712105/linq-to-sql-exception-local-sequence-cannot-be-used-in-linq-to-sql-implementatio Let's say I have following: var a = new [] { 1, 4, 7 }; var b = new [] { 2, 5, 8 }; var test = from i in a from j in b select new { A = i, B = j, AB = string.Format("{0:00}a{1:00}b", i, j), }; foreach (var t in test) Console.Write("{0}, ", t.AB); This works great and I get a dump like so (note, I want the cartesian product): 01a02b, 01a05b, 01a08b, 04a02b, 04a05b, 04a08b, 07a02b, 07a05b, 07a08b, Now what I really want is to take this and cartesian product it again against an ID from a database table I have. But, as soon as I add in one more from clause that instead of referencing objects, references SQL table, I get an error. So, altering above to something like so where db is defined as a new DataContext (i.e., class deriving from System.Data.Linq.DataContext): var a = new [] { 1, 4, 7 }; var b = new [] { 2, 5, 8 }; var test = from symbol in db.Symbols from i in a from j in b select new { A = i, B = j, AB = string.Format("{0}{1:00}a{2:00}b", symbol.ID, i, j), }; foreach (var t in test) Console.Write("{0}, ", t.AB); The error I get is following: Local sequence cannot be used in LINQ to SQL implementations of query operators except the Contains operator Its related to not using Contains apparently but I'm unsure how Contains would be used when I don't really want to constrict the results - I want the Cartesian product for my situation. Any ideas of how to use Contains above and still yield the Cartesian product when joining database and local sequences?

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• Using LINQ in generic collections

  - by Hugo S Ferreira

  Hi, Please consider the following snippet from an implementation of the Interpreter pattern: public override object Execute(Interpreter interpreter, object ctx) { var list = ctx as IEnumerable<string>; return (list != null) ? list.FirstOrDefault() : null; } What about if I want to use the same function for integers? public override object Execute(Interpreter interpreter, object ctx) { var list = ctx as IEnumerable<string>; if (list != null) return list.FirstOrDefault(); var list = ctx as IEnumerable<int>; return (list != null) ? list.FirstOrDefault() : null; } What I wanted was something like: public override object Execute(Interpreter interpreter, object ctx) { var list = ctx as IEnumerable; return (list != null) ? list.FirstOrDefault() : null; } But Linq doesn't act on IEnumerables. Instead, to get to this solution, I would be forced to write something like: public override object Execute(Interpreter interpreter, object ctx) { var list = ctx as IEnumerable; if (list != null) foreach(var i in list) { yield return i; return; } return null; } Or use a generic method: public override T Execute<T>(Interpreter interpreter, object ctx) { var list = ctx as IEnumerable<T>; return (list != null) ? list.FirstOrDefault() : null; } Which would break the Interpreter pattern (as it was implemented in this system). Covariance would also fail (at least in C#3), though would it work, it would be the exact behavior I wanted: public override object Execute(Interpreter interpreter, object ctx) { var list = ctx as IEnumerable<object>; return (list != null) ? list.FirstOrDefault() : null; } So, my question is: what's the best way to achieve the intended behavior? Thanks :-)

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• C# Thread-safe Extension Method

  - by Wonko the Sane

  Hello All, I may be waaaay off, or else really close. Either way, I'm currently SOL. :) I want to be able to use an extension method to set properties on a class, but that class may (or may not) be updated on a non-UI thread, and derives from a class the enforces updates to be on the UI thread (which implements INotifyPropertyChanged, etc). I have a class defined something like this: public class ClassToUpdate : UIObservableItem { private readonly Dispatcher mDispatcher = Dispatcher.CurrentDispatcher; private Boolean mPropertyToUpdate = false; public ClassToUpdate() : base() { } public Dispatcher Dispatcher { get { return mDispatcher; } } public Boolean PropertyToUpdate { get { return mPropertyToUpdate; } set { SetValue("PropertyToUpdate", ref mPropertyToUpdate, value; } } } I have an extension method class defined something like this: static class ExtensionMethods { public static IEnumerable<T> SetMyProperty<T>(this IEnumerable<T> sourceList, Boolean newValue) { ClassToUpdate firstClass = sourceList.FirstOrDefault() as ClassToUpdate; if (firstClass.Dispatcher.Thread.ManagedThreadId != System.Threading.Thread.CurrentThread.ManagedThreadId) { // WHAT GOES HERE? } else { foreach (var classToUpdate in sourceList) { (classToUpdate as ClassToUpdate ).PropertyToUpdate = newValue; yield return classToUpdate; } } } } Obviously, I'm looking for the "WHAT GOES HERE" in the extension method. Thanks, wTs

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• ASP.NET putting dynamic controls on page in reverse messes up events

  - by Jimmy Geels

  I have this weird problem when putting textboxes on the page in reverse. The whole event system is messed up. Changing one textbox fires TextChange on all textboxes. I can fix this by putting the controls in a list first and then call add while iterating trough the list in reverse. But i just want to know why this fails. Heres some code (.net 2.0) public partial class _Default : Page { protected void Page_Load(object sender, EventArgs e) { InitFields(); } private void InitFields() { int nrFields; //We have a static textbox called nrElements, this determines the number //of fields to initialize if (int.TryParse(nrElements.Text, out nrFields)) { //Put all the dynamic fields on the screen in reverse order foreach(Control t in GetDynamicFields(nrFields)) { //Calling Controls.Add works fine //Calling Controls.AddAt messes up the events //Try changing different textboxes plhFields.Controls.AddAt(0, t); } } } private IEnumerable<Control> GetDynamicFields(int nrFields) { for (int i = 0; i < nrFields; i++) { TextBox txtBox = new TextBox(); txtBox.ID = string.Format("dynTextBox{0}", i.ToString()); txtBox.AutoPostBack = true; txtBox.TextChanged += t_TextChanged; yield return txtBox; } } private void t_TextChanged(object sender, EventArgs e) { TextBox txtBox = sender as TextBox; if (txtBox != null) txtBox.Text = txtBox.Text + "Changed "; } }

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• Hyperlink regex including http(s):// not working in C#

  - by Rory Fitzpatrick

  I think this is sufficiently different from similar questions to warrant a new one. I have the following regex to match the beginning hyperlink tags in HTML, including the http(s):// part in order to avoid mailto: links <a[^>]*?href=[""'](?<href>\\b(https?)://[^\[\]""]+?)[""'][^>]*?> When I run this through Nregex (with escaping removed) it matches correctly for the following test cases: <a href="http://www.bbc.co.uk"> <a href="http://bbc.co.uk"> <a href="https://www.bbc.co.uk"> <a href="mailto:[email protected]"> However when I run this in my C# code it fails. Here is the matching code: public static IEnumerable<string> GetUrls(this string input, string matchPattern) { var matches = Regex.Matches(input, matchPattern, RegexOptions.Compiled | RegexOptions.IgnoreCase); foreach (Match match in matches) { yield return match.Groups["href"].Value; } } And my tests: @"<a href=""https://www.bbc.co.uk"">bbc</a>".GetUrls(StringExtensions.HtmlUrlRegexPattern).Count().ShouldEqual(1); @"<a href=""mailto:[email protected]"">bbc</a>".GetUrls(StringExtensions.HtmlUrlRegexPattern).Count().ShouldEqual(0); The problem seems to be in the \\b(https?):// part which I added, removing this passes the normal URL test but fails the mailto: test. Anyone shed any light?

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• XmlSlurper/NekoHTML document fragment parsing - No HTML or BODY tags wanted

  - by Misha Koshelev

  Dear All, I am trying to parse the following HTML fragment, and I would like to get the same fragment as output (without HTML and BODY tags). Is this possible? If so, how? Thank you Misha p.s. I am reading here: http://nekohtml.sourceforge.net/faq.html#fragments and I believe I have added the correct options below. However, the output is still incorrect :( Thank you Misha import groovy.xml.MarkupBuilder import groovy.xml.StreamingMarkupBuilder import groovy.util.XmlNodePrinter import groovy.util.slurpersupport.NodeChild def text=""" <div><h2>Test</h2> <div>Hi</div> </div> """ // Parse def config=new org.cyberneko.html.HTMLConfiguration() config.setFeature("http://cyberneko.org/html/features/balance-tags/document-fragment",true) def html=new XmlSlurper(new org.cyberneko.html.parsers.SAXParser()).parseText(text) // Output def printNode(NodeChild node) { def writer = new StringWriter() writer << new StreamingMarkupBuilder().bind { mkp.declareNamespace('':node[0].namespaceURI()) mkp.yield node } new XmlNodePrinter().print(new XmlParser().parseText(writer.toString())) } printNode(html) Output: <HTML> <tag0:HEAD xmlns:tag0="http://www.w3.org/1999/xhtml"/> <BODY> <DIV> <H2> Test </H2> <DIV> Hi </DIV> </DIV> </BODY> </HTML>

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• Advice welcomed on creating my own Swing component

  - by Toto

  Recently I asked which was the best Swing component to bind to a BigDecimal variable (with some particular editing properties). It turns out that none of the standard Swing components suit me completely, nor did the third-party Swing component libraries I've found out there. So I’ve decided to create my own Swing component. Component description: I want to extend JTextField or JFormattedTextField, so my new component can be easily bound to a BigDecimal variable. The component will have customizable scale and length properties. Behavior: When the component is drawn, it shows only the decimal point and space for scale digits to its right. When the component receives focus the caret should be positioned left to the decimal point. As the user types numbers (any other character is ignored) they appear to the left of the caret, only length – scale numbers are accepted, any other number typed is ignored as the integer portion is full. Any time the user types the decimal point the caret moves to the right side of the decimal point. The following numbers typed are shown in the decimal part, only scale numbers are considered any other number typed is ignored as the decimal portion is full. Additionally, thousand separators should appear as the user types numbers left to the decimal point. Invoking a getValue() method on the component should yield the BigDecimal representing the number just entered. I’ve never created my own Swing component; I’ve barely used the standard ones. So I would appreciate any good tutorial/info/tip on creating the component described. This is the only thing I've got so far. Thanks in advance.

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• Reading Data from DDFS ValueError: No JSON object could be decoded

  - by secumind

  I'm running dozens of map reduce jobs for a number of different purposes using disco. My data has grown enormous and I thought I would try using DDFS for a change rather than standard txt files. I've followed the DISCO map/reduce example Counting Words as a map/reduce job, without to much difficulty and with the help of others, Reading JSON specific data into DISCO I've gotten past one of my latest problems. I'm trying to read data in/out of ddfs to better chunk and distribute it but am having a bit of trouble. Here's an example file: file.txt {"favorited": false, "in_reply_to_user_id": null, "contributors": null, "truncated": false, "text": "I'll call him back tomorrow I guess", "created_at": "Mon Feb 13 05:34:27 +0000 2012", "retweeted": false, "in_reply_to_status_id_str": null, "coordinates": null, "in_reply_to_user_id_str": null, "entities": {"user_mentions": [], "hashtags": [], "urls": []}, "in_reply_to_status_id": null, "id_str": "168931016843603968", "place": null, "user": {"follow_request_sent": null, "profile_use_background_image": true, "profile_background_image_url_https": "https://si0.twimg.com/profile_background_images/305726905/FASHION-3.png", "verified": false, "profile_image_url_https": "https://si0.twimg.com/profile_images/1818996723/image_normal.jpg", "profile_sidebar_fill_color": "292727", "is_translator": false, "id": 113532729, "profile_text_color": "000000", "followers_count": 78, "protected": false, "location": "With My Niggas In Paris!", "default_profile_image": false, "listed_count": 0, "utc_offset": -21600, "statuses_count": 6733, "description": "Made in CHINA., Educated && Making My Own $$. Fear GOD && Put Him 1st. #TeamFollowBack #TeamiPhone\n", "friends_count": 74, "profile_link_color": "b03f3f", "profile_image_url": "http://a2.twimg.com/profile_images/1818996723/image_normal.jpg", "notifications": null, "show_all_inline_media": false, "geo_enabled": true, "profile_background_color": "1f9199", "id_str": "113532729", "profile_background_image_url": "http://a3.twimg.com/profile_background_images/305726905/FASHION-3.png", "name": "Bee'Jay", "lang": "en", "profile_background_tile": true, "favourites_count": 19, "screen_name": "OohMyBEEsNice", "url": "http://www.bitchimpaid.org", "created_at": "Fri Feb 12 03:32:54 +0000 2010", "contributors_enabled": false, "time_zone": "Central Time (US & Canada)", "profile_sidebar_border_color": "000000", "default_profile": false, "following": null}, "in_reply_to_screen_name": null, "retweet_count": 0, "geo": null, "id": 168931016843603968, "source": "<a href=\"http://twitter.com/#!/download/iphone\" rel=\"nofollow\">Twitter for iPhone</a>"} {"favorited": false, "in_reply_to_user_id": 50940453, "contributors": null, "truncated": false, "text": "@LegaMrvica @MimozaBand makasi om artis :D kadoo kadoo", "created_at": "Mon Feb 13 05:34:27 +0000 2012", "retweeted": false, "in_reply_to_status_id_str": "168653037894770688", "coordinates": null, "in_reply_to_user_id_str": "50940453", "entities": {"user_mentions": [{"indices": [0, 11], "screen_name": "LegaMrvica", "id": 50940453, "name": "Lega_thePianis", "id_str": "50940453"}, {"indices": [12, 23], "screen_name": "MimozaBand", "id": 375128905, "name": "Mimoza", "id_str": "375128905"}], "hashtags": [], "urls": []}, "in_reply_to_status_id": 168653037894770688, "id_str": "168931016868761600", "place": null, "user": {"follow_request_sent": null, "profile_use_background_image": true, "profile_background_image_url_https": "https://si0.twimg.com/profile_background_images/347686061/Galungan_dan_Kuningan.jpg", "verified": false, "profile_image_url_https": "https://si0.twimg.com/profile_images/1803845596/Picture_20124_normal.jpg", "profile_sidebar_fill_color": "DDFFCC", "is_translator": false, "id": 48293450, "profile_text_color": "333333", "followers_count": 182, "protected": false, "location": "\u00dcT: -6.906799,107.622383", "default_profile_image": false, "listed_count": 0, "utc_offset": -28800, "statuses_count": 3052, "description": "Fashion design maranatha '11 // traditional dancer (bali) at sanggar tampak siring & Natya Nataraja", "friends_count": 206, "profile_link_color": "0084B4", "profile_image_url": "http://a3.twimg.com/profile_images/1803845596/Picture_20124_normal.jpg", "notifications": null, "show_all_inline_media": false, "geo_enabled": true, "profile_background_color": "9AE4E8", "id_str": "48293450", "profile_background_image_url": "http://a0.twimg.com/profile_background_images/347686061/Galungan_dan_Kuningan.jpg", "name": "nana afiff", "lang": "en", "profile_background_tile": true, "favourites_count": 2, "screen_name": "hasnfebria", "url": null, "created_at": "Thu Jun 18 08:50:29 +0000 2009", "contributors_enabled": false, "time_zone": "Pacific Time (US & Canada)", "profile_sidebar_border_color": "BDDCAD", "default_profile": false, "following": null}, "in_reply_to_screen_name": "LegaMrvica", "retweet_count": 0, "geo": null, "id": 168931016868761600, "source": "<a href=\"http://blackberry.com/twitter\" rel=\"nofollow\">Twitter for BlackBerry\u00ae</a>"} {"favorited": false, "in_reply_to_user_id": 27260086, "contributors": null, "truncated": false, "text": "@justinbieber u were born to be somebody, and u're super important in beliebers' life. thanks for all biebs. I love u. follow me? 84", "created_at": "Mon Feb 13 05:34:27 +0000 2012", "retweeted": false, "in_reply_to_status_id_str": null, "coordinates": null, "in_reply_to_user_id_str": "27260086", "entities": {"user_mentions": [{"indices": [0, 13], "screen_name": "justinbieber", "id": 27260086, "name": "Justin Bieber", "id_str": "27260086"}], "hashtags": [], "urls": []}, "in_reply_to_status_id": null, "id_str": "168931016856178688", "place": null, "user": {"follow_request_sent": null, "profile_use_background_image": true, "profile_background_image_url_https": "https://si0.twimg.com/profile_background_images/416005864/Captura.JPG", "verified": false, "profile_image_url_https": "https://si0.twimg.com/profile_images/1808883280/Captura6_normal.JPG", "profile_sidebar_fill_color": "f5e7f3", "is_translator": false, "id": 406750700, "profile_text_color": "333333", "followers_count": 1122, "protected": false, "location": "Adentro de una supra.", "default_profile_image": false, "listed_count": 0, "utc_offset": -14400, "statuses_count": 20966, "description": "Mi \u00eddolo es @justinbieber , si te gusta \u00a1genial!, si no, solo respetalo. El cambi\u00f3 mi vida completamente y mi sue\u00f1o es conocerlo #TrueBelieber . ", "friends_count": 1015, "profile_link_color": "9404b8", "profile_image_url": "http://a1.twimg.com/profile_images/1808883280/Captura6_normal.JPG", "notifications": null, "show_all_inline_media": false, "geo_enabled": false, "profile_background_color": "f9fcfa", "id_str": "406750700", "profile_background_image_url": "http://a3.twimg.com/profile_background_images/416005864/Captura.JPG", "name": "neversaynever,right?", "lang": "es", "profile_background_tile": false, "favourites_count": 22, "screen_name": "True_Belieebers", "url": "http://www.wehavebieber-fever.tumblr.com", "created_at": "Mon Nov 07 04:17:40 +0000 2011", "contributors_enabled": false, "time_zone": "Santiago", "profile_sidebar_border_color": "C0DEED", "default_profile": false, "following": null}, "in_reply_to_screen_name": "justinbieber", "retweet_count": 0, "geo": null, "id": 168931016856178688, "source": "<a href=\"http://yfrog.com\" rel=\"nofollow\">Yfrog</a>"} I load it into DDFS with: # ddfs chunk data:test1 ./file.txt created: disco://localhost/ddfs/vol0/blob/44/file_txt-0$549-db27b-125e1 I test that the file is indeed loaded into ddfs with: # ddfs xcat data:test1 {"favorited": false, "in_reply_to_user_id": null, "contributors": null, "truncated": false, "text": "I'll call him back tomorrow I guess", "created_at": "Mon Feb 13 05:34:27 +0000 2012", "retweeted": false, "in_reply_to_status_id_str": null, "coordinates": null, "in_reply_to_user_id_str": null, "entities": {"user_mentions": [], "hashtags": [], "urls": []}, "in_reply_to_status_id": null, "id_str": "168931016843603968", "place": null, "user": {"follow_request_sent": null, "profile_use_background_image": true, "profile_background_image_url_https": "https://si0.twimg.com/profile_background_images/305726905/FASHION-3.png", "verified": false, "profile_image_url_https": "https://si0.twimg.com/profile_images/1818996723/image_normal.jpg", "profile_sidebar_fill_color": "292727", "is_translator": false, "id": 113532729, "profile_text_color": "000000", "followers_count": 78, "protected": false, "location": "With My Niggas In Paris!", "default_profile_image": false, "listed_count": 0, "utc_offset": -21600, "statuses_count": 6733, "description": "Made in CHINA., Educated && Making My Own $$. Fear GOD && Put Him 1st. #TeamFollowBack #TeamiPhone\n", "friends_count": 74, "profile_link_color": "b03f3f", "profile_image_url": "http://a2.twimg.com/profile_images/1818996723/image_normal.jpg", "notifications": null, "show_all_inline_media": false, "geo_enabled": true, "profile_background_color": "1f9199", "id_str": "113532729", "profile_background_image_url": "http://a3.twimg.com/profile_background_images/305726905/FASHION-3.png", "name": "Bee'Jay", "lang": "en", "profile_background_tile": true, "favourites_count": 19, "screen_name": "OohMyBEEsNice", "url": "http://www.bitchimpaid.org", "created_at": "Fri Feb 12 03:32:54 +0000 2010", "contributors_enabled": false, "time_zone": "Central Time (US & Canada)", "profile_sidebar_border_color": "000000", "default_profile": false, "following": null}, "in_reply_to_screen_name": null, "retweet_count": 0, "geo": null, "id": 168931016843603968, "source": "<a href=\"http://twitter.com/#!/download/iphone\" rel=\"nofollow\">Twitter for iPhone</a>"} {"favorited": false, "in_reply_to_user_id": 50940453, "contributors": null, "truncated": false, "text": "@LegaMrvica @MimozaBand makasi om artis :D kadoo kadoo", "created_at": "Mon Feb 13 05:34:27 +0000 2012", "retweeted": false, "in_reply_to_status_id_str": "168653037894770688", "coordinates": null, "in_reply_to_user_id_str": "50940453", "entities": {"user_mentions": [{"indices": [0, 11], "screen_name": "LegaMrvica", "id": 50940453, "name": "Lega_thePianis", "id_str": "50940453"}, {"indices": [12, 23], "screen_name": "MimozaBand", "id": 375128905, "name": "Mimoza", "id_str": "375128905"}], "hashtags": [], "urls": []}, "in_reply_to_status_id": 168653037894770688, "id_str": "168931016868761600", "place": null, "user": {"follow_request_sent": null, "profile_use_background_image": true, "profile_background_image_url_https": "https://si0.twimg.com/profile_background_images/347686061/Galungan_dan_Kuningan.jpg", "verified": false, "profile_image_url_https": "https://si0.twimg.com/profile_images/1803845596/Picture_20124_normal.jpg", "profile_sidebar_fill_color": "DDFFCC", "is_translator": false, "id": 48293450, "profile_text_color": "333333", "followers_count": 182, "protected": false, "location": "\u00dcT: -6.906799,107.622383", "default_profile_image": false, "listed_count": 0, "utc_offset": -28800, "statuses_count": 3052, "description": "Fashion design maranatha '11 // traditional dancer (bali) at sanggar tampak siring & Natya Nataraja", "friends_count": 206, "profile_link_color": "0084B4", "profile_image_url": "http://a3.twimg.com/profile_images/1803845596/Picture_20124_normal.jpg", "notifications": null, "show_all_inline_media": false, "geo_enabled": true, "profile_background_color": "9AE4E8", "id_str": "48293450", "profile_background_image_url": "http://a0.twimg.com/profile_background_images/347686061/Galungan_dan_Kuningan.jpg", "name": "nana afiff", "lang": "en", "profile_background_tile": true, "favourites_count": 2, "screen_name": "hasnfebria", "url": null, "created_at": "Thu Jun 18 08:50:29 +0000 2009", "contributors_enabled": false, "time_zone": "Pacific Time (US & Canada)", "profile_sidebar_border_color": "BDDCAD", "default_profile": false, "following": null}, "in_reply_to_screen_name": "LegaMrvica", "retweet_count": 0, "geo": null, "id": 168931016868761600, "source": "<a href=\"http://blackberry.com/twitter\" rel=\"nofollow\">Twitter for BlackBerry\u00ae</a>"} {"favorited": false, "in_reply_to_user_id": 27260086, "contributors": null, "truncated": false, "text": "@justinbieber u were born to be somebody, and u're super important in beliebers' life. thanks for all biebs. I love u. follow me? 84", "created_at": "Mon Feb 13 05:34:27 +0000 2012", "retweeted": false, "in_reply_to_status_id_str": null, "coordinates": null, "in_reply_to_user_id_str": "27260086", "entities": {"user_mentions": [{"indices": [0, 13], "screen_name": "justinbieber", "id": 27260086, "name": "Justin Bieber", "id_str": "27260086"}], "hashtags": [], "urls": []}, "in_reply_to_status_id": null, "id_str": "168931016856178688", "place": null, "user": {"follow_request_sent": null, "profile_use_background_image": true, "profile_background_image_url_https": "https://si0.twimg.com/profile_background_images/416005864/Captura.JPG", "verified": false, "profile_image_url_https": "https://si0.twimg.com/profile_images/1808883280/Captura6_normal.JPG", "profile_sidebar_fill_color": "f5e7f3", "is_translator": false, "id": 406750700, "profile_text_color": "333333", "followers_count": 1122, "protected": false, "location": "Adentro de una supra.", "default_profile_image": false, "listed_count": 0, "utc_offset": -14400, "statuses_count": 20966, "description": "Mi \u00eddolo es @justinbieber , si te gusta \u00a1genial!, si no, solo respetalo. El cambi\u00f3 mi vida completamente y mi sue\u00f1o es conocerlo #TrueBelieber . ", "friends_count": 1015, "profile_link_color": "9404b8", "profile_image_url": "http://a1.twimg.com/profile_images/1808883280/Captura6_normal.JPG", "notifications": null, "show_all_inline_media": false, "geo_enabled": false, "profile_background_color": "f9fcfa", "id_str": "406750700", "profile_background_image_url": "http://a3.twimg.com/profile_background_images/416005864/Captura.JPG", "name": "neversaynever,right?", "lang": "es", "profile_background_tile": false, "favourites_count": 22, "screen_name": "True_Belieebers", "url": "http://www.wehavebieber-fever.tumblr.com", "created_at": "Mon Nov 07 04:17:40 +0000 2011", "contributors_enabled": false, "time_zone": "Santiago", "profile_sidebar_border_color": "C0DEED", "default_profile": false, "following": null}, "in_reply_to_screen_name": "justinbieber", "retweet_count": 0, "geo": null, "id": 168931016856178688, "source": "<a href=\"http://yfrog.com\" rel=\"nofollow\">Yfrog</a> At this point everything is great, I load up the script that resulted from a previous Stack Post: from disco.core import Job, result_iterator import gzip def map(line, params): import unicodedata import json r = json.loads(line).get('text') s = unicodedata.normalize('NFD', r).encode('ascii', 'ignore') for word in s.split(): yield word, 1 def reduce(iter, params): from disco.util import kvgroup for word, counts in kvgroup(sorted(iter)): yield word, sum(counts) if __name__ == '__main__': job = Job().run(input=["tag://data:test1"], map=map, reduce=reduce) for word, count in result_iterator(job.wait(show=True)): print word, count NOTE: That this script runs file if the input=["file.txt"], however when I run it with "tag://data:test1" I get the following error: # DISCO_EVENTS=1 python count_normal_words.py Job@549:db30e:25bd8: Status: [map] 0 waiting, 1 running, 0 done, 0 failed 2012/11/25 21:43:26 master New job initialized! 2012/11/25 21:43:26 master Starting job 2012/11/25 21:43:26 master Starting map phase 2012/11/25 21:43:26 master map:0 assigned to solice 2012/11/25 21:43:26 master ERROR: Job failed: Worker at 'solice' died: Traceback (most recent call last): File "/home/DISCO/data/solice/01/Job@549:db30e:25bd8/usr/local/lib/python2.7/site-packages/disco/worker/__init__.py", line 329, in main job.worker.start(task, job, **jobargs) File "/home/DISCO/data/solice/01/Job@549:db30e:25bd8/usr/local/lib/python2.7/site-packages/disco/worker/__init__.py", line 290, in start self.run(task, job, **jobargs) File "/home/DISCO/data/solice/01/Job@549:db30e:25bd8/usr/local/lib/python2.7/site-packages/disco/worker/classic/worker.py", line 286, in run getattr(self, task.mode)(task, params) File "/home/DISCO/data/solice/01/Job@549:db30e:25bd8/usr/local/lib/python2.7/site-packages/disco/worker/classic/worker.py", line 299, in map for key, val in self['map'](entry, params): File "count_normal_words.py", line 12, in map File "/usr/lib64/python2.7/json/__init__.py", line 326, in loads return _default_decoder.decode(s) File "/usr/lib64/python2.7/json/decoder.py", line 366, in decode obj, end = self.raw_decode(s, idx=_w(s, 0).end()) File "/usr/lib64/python2.7/json/decoder.py", line 384, in raw_decode raise ValueError("No JSON object could be decoded") ValueError: No JSON object could be decoded 2012/11/25 21:43:26 master WARN: Job killed Status: [map] 1 waiting, 0 running, 0 done, 1 failed Traceback (most recent call last): File "count_normal_words.py", line 28, in <module> for word, count in result_iterator(job.wait(show=True)): File "/usr/local/lib/python2.7/site-packages/disco/core.py", line 348, in wait timeout, poll_interval * 1000) File "/usr/local/lib/python2.7/site-packages/disco/core.py", line 309, in check_results raise JobError(Job(name=jobname, master=self), "Status %s" % status) disco.error.JobError: Job Job@549:db30e:25bd8 failed: Status dead The Error states: ValueError: No JSON object could be decoded. Again, this works fine using the text file as input but now DDFS. Any ideas, I'm open to suggestions?

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• How can I capture Rake output when invoked from with a Ruby script?

  - by Adrian O'Connor

  I am writing a web-based dev-console for Rails development. In one of my controller actions, I am calling Rake, but I am unable to capture any of the output that Rake generates. For example, here is some sample code, from the controller: require 'rake' require 'rake/rdoctask' require 'rake/testtask' require 'tasks/rails' require 'stringio' ... def show_routes @results = capture_stdout { Rake.tasks['routes'].invoke } # @results is nil -- the capture_stdout doesn't catpure anything that Rake generates end def capture_stdout s = StringIO.new $stdout = s yield s.string ensure $stdout = STDOUT end Does anybody know why I can't capture the Rake output? I've tried going through the Rake source, and I can't see where it fires a new process or anything, so I think I ought to be able to do this. Many thanks! Adrian I have since discovered the correct way to call Rake from inside Ruby that works much better: Rake.application['db:migrate:redo'].reenable Rake.application['db:migrate:redo'].invoke Strangely, some rake tasks work perfectly now (routes), some capture the output the first time the run and after that are always blank (db:migrate:redo) and some don't seem to ever capture output (test). Odd.

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• Pair-wise iteration in C# or sliding window enumerator

  - by f3lix

  If I have an IEnumerable like: string[] items = new string[] { "a", "b", "c", "d" }; I would like to loop thru all the pairs of consecutive items (sliding window of size 2). Which would be ("a","b"), ("b", "c"), ("c", "d") My solution was is this public static IEnumerable<Pair<T, T>> Pairs(IEnumerable<T> enumerable) { IEnumerator<T> e = enumerable.GetEnumerator(); e.MoveNext(); T current = e.Current; while ( e.MoveNext() ) { T next = e.Current; yield return new Pair<T, T>(current, next); current = next; } } // used like this : foreach (Pair<String,String> pair in IterTools<String>.Pairs(items)) { System.Out.PrintLine("{0}, {1}", pair.First, pair.Second) } When I wrote this code, I wondered if there are already functions in the .NET framework that do the same thing and do it not just for pairs but for any size tuples. IMHO there should be a nice way to do this kind of sliding window operations. I use C# 2.0 and I can imagine that with C# 3.0 (w/ LINQ) there are more (and nicer) ways to do this, but I'm primarily interested in C# 2.0 solutions. Though, I will also appreciate C# 3.0 solutions.

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• Joining the previous and next sentence using python

  - by JudoWill

  I'm trying to join a set of sentences contained in a list. I have a function which determines whether a sentence in worth saving. However, in order to keep the context of the sentence I need to also keep the sentence before and after it. In the edge cases, where its either the first or last sentence then, I'll just keep the sentence and its only neighbor. An example is best: ex_paragraph = ['The quick brown fox jumps over the fence.', 'Where there is another red fox.', 'They run off together.', 'They live hapily ever after.'] t1 = lambda x: x.startswith('Where') t2 = lambda x: x'startswith('The ') The result for t1 should be: ['The quick brown fox jumps over the fence. Where there is another red fox. They run off together.'] The result for t2 should be: ['The quick brown fox jumps over the fence. Where there is another red fox.'] My solution is: def YieldContext(sent_list, cont_fun): def JoinSent(sent_list, ind): if ind == 0: return sent_list[ind]+sent_list[ind+1] elif ind == len(sent_list)-1: return sent_list[ind-1]+sent_list[ind] else: return ' '.join(sent_list[ind-1:ind+1]) for sent, sentnum in izip(sent_list, count(0)): if cont_fun(sent): yield JoinSent(sent_list, sent_num) Does anyone know a "cleaner" or more pythonic way to do something like this. The if-elif-else seems a little forced. Thanks, Will PS. I'm obviously doing this with a more complicated "context-function" but this is just for a simple example.

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• A UnicodeDecodeError that occurs with json in python on Windows, but not Mac.

  - by ventolin

  On windows, I have the following problem: >>> string = "Don´t Forget To Breathe" >>> import json,os,codecs >>> f = codecs.open("C:\\temp.txt","w","UTF-8") >>> json.dump(string,f) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "C:\Python26\lib\json\__init__.py", line 180, in dump for chunk in iterable: File "C:\Python26\lib\json\encoder.py", line 294, in _iterencode yield encoder(o) UnicodeDecodeError: 'utf8' codec can't decode bytes in position 3-5: invalid data (Notice the non-ascii apostrophe in the string.) However, my friend, on his mac (also using python2.6), can run through this like a breeze: > string = "Don´t Forget To Breathe" > import json,os,codecs > f = codecs.open("/tmp/temp.txt","w","UTF-8") > json.dump(string,f) > f.close(); open('/tmp/temp.txt').read() '"Don\\u00b4t Forget To Breathe"' Why is this? I've also tried using UTF-16 and UTF-32 with json and codecs, but to no avail.

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• How to make Resig's micro-templates XHTML compliant?

  - by mshelv

  Hello, I have been experimenting with John Resig's micro-template, which works great. However, the mark-up will not pass the XHTML 1.0 Transitional validation test. (Among other things, id attributes yield errors.) Replacing tags identifiers <, with [[,]], passes validation. Thus, I created a js script which at load time (jQuery document ready) converts the square brackets back to regular markers. This works fine in FF, but not in IE, Chrome, etc. Scripts embedded within CDATA tags validate as well. Question: Is there a way to insert micro-template in a script and still pass XHTML validation? My idea was to remove the CDATA tags once the page has been loaded. But there are probably smarter ways. (Note: I'd prefer not to inject HTML via js since the mark-up will be difficult to maintain.) PS: I looked at other js templates, but they are either not XHTML compliant or too bulky. TIA for any hints.

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• Building an extension framework for a Rails app

  - by obvio171

  I'm starting research on what I'd need in order to build a user-level plugin system (like Wordpress plugins) for a Rails app, so I'd appreciate some general pointers/advice. By user-level plugin I mean a package a user can extract into a folder and have it show up on an admin interface, allowing them to add some extra configuration and then activate it. What is the best way to go about doing this? Is there any other opensource project that does this already? What does Rails itself already offer for programmer-level plugins that could be leveraged? Any Rails plugins that could help me with this? A plugin would have to be able to: run its own migrations (with this? it's undocumented) have access to my models (plugins already do) have entry points for adding content to views (can be done with content_for and yield) replace entire views or partials (how?) provide its own admin and user-facing views (how?) create its own routes (or maybe just announce its presence and let me create the routes for it, to avoid plugins stepping on each other's toes) Anything else I'm missing? Also, is there a way to limit which tables/actions the plugin has access to concerning migrations and models, and also limit their access to routes (maybe letting them include, but not remove routes)? P.S.: I'll try to keep this updated, compiling stuff I figure out and relevant answers so as to have a sort of guide for others.

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• Array Recursion

  - by GeeYouAreYou

  I've got an assignment I can't figure out, any pointers will be much appreciated, it goes like so: There's a series of light bulbs represented as an array of true/false, there's a switch for every light bulb, by clicking it for any light bulb, you toggle it as well as 2 adjacent ones (1 from left & another 1 from right; if clicked switch's bulb on edge -- only 1 adjacent toggled of course). What is needed to accomplish is a method that accepts an array of a series of turned on/off light bulbs and another one representing another state of supposedly the 1st array after some switches have been clicked..! So recursion must be used to find out whether there's a combination of switch clicks that will transform array 1 to array 2. Here's the signature of the method: public static boolean disco(boolean[] init, boolean[] target) Will return true if array init can be transformed to target, false otherwise. Method must be static and not use any other static and global variables, only local. Example: boolean[] init = {true, false, true, false, true, false}; boolean[] target = {false, true, false, true, false, true}; For above 2 arrays, disco(init, target) will return true because toggling the 1st and 4th bulbs would yield the target state (remember adjacent bulbs being toggled as well). Any help much appreciated..!!

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• Dependency Injection for objects that require parameters

  - by Andrew

  All of our reports are created from object graphs that are translated from our domain objects. To enable this, we have a Translator class for each report, and have been using Dependency Injection for passing in dependencies. This worked great, and would yield nice classes structured like this: public class CheckTranslator : ICheckTranslator { public CheckTranslator (IEmployeeService empSvc , IPaycheckService paySvc) { _empSvc = empSvc; _paySvc = paySvc; } public Check CreateCheck() { //do the translation... } } However, in some cases the mapping has many different grouping options. As a result, the c-tor would turn into a mix of class dependencies and parameters. public class CheckTranslator : ICheckTranslator { public CheckTranslator (IEmployeeService empSvc , IPaycheckService paySvc , bool doTranslateStubData , bool doAttachLogo) { _empSvc = empSvc; _paySvc = paySvc; _doTranslateStubData = doTranslateStubData; _doAttachLogo = doAttachLogo; } public Check CreateCheck() { //do the translation... } } Now, we can still test it, but it no longer really works with an IoC container, at least in a clean fashion. Plus, we can no longer call the CreateCheck twice if the settings are different for each check. While I recognize it's a problem, I don't necessarily see the right solution. It seems kind of strange to create a Factory for each class ... or is this the best way?

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• When to use "property" builtin: auxiliary functions and generators

  - by Seth Johnson

  I recently discovered Python's property built-in, which disguises class method getters and setters as a class's property. I'm now being tempted to use it in ways that I'm pretty sure are inappropriate. Using the property keyword is clearly the right thing to do if class A has a property _x whose allowable values you want to restrict; i.e., it would replace the getX() and setX() construction one might write in C++. But where else is it appropriate to make a function a property? For example, if you have class Vertex(object): def __init__(self): self.x = 0.0 self.y = 1.0 class Polygon(object): def __init__(self, list_of_vertices): self.vertices = list_of_vertices def get_vertex_positions(self): return zip( *( (v.x,v.y) for v in self.vertices ) ) is it appropriate to add vertex_positions = property( get_vertex_positions ) ? Is it ever ok to make a generator look like a property? Imagine if a change in our code meant that we no longer stored Polygon.vertices the same way. Would it then be ok to add this to Polygon? @property def vertices(self): for v in self._new_v_thing: yield v.calculate_equivalent_vertex()

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