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  • How Can I List a TDictionary in Alphabetical Order by Key in Delphi 2009?

    - by lkessler
    How can I use a TEnumerator to go through my TDictionary in sorted order by key? I've got something like this: var Dic: TDictionary<string, string>; begin Dic := TDictionary<string, string>.create; Dic.Add('Tired', 'I have been working on this too long'); Dic.Add('Early', 'It is too early in the morning to be working on this'); Dic.Add('HelpMe', 'I need some help'); Dic.Add('Dumb', 'Yes I know this example is dumb'); { The following is what I don't know how to do } for each string1 (ordered by string1) in Dic do some processing with the current Dic element Dic.Free; end; So I would like to process my dictionary in the order: Dumb, Early, HelpMe, Tired. Unfortunately the Delphi help is very minimal in describing how TEnumerator works and gives no examples that I can find. There is also very little written on the web about using Enumerators with Generics in Delphi.

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  • Need to parse HTML document for links-- use a library like html5lib or something else?

    - by Luinithil
    I'm a very newbie webpage builder, currently working on creating a website that needs to change link colours according to the destination page. The links will be sorted into different classes (e.g. good, bad, neutral) by certain user input criteria-- e.g. links with content the user would find of interest is colored blue, stuff that the user (presumably) doesn't want to see is colored as normal text, etc. I reckon I need a way to parse the webpage for links to the content (stored in MySQL database), change the colors for all the links on the page (so I need to be able to change the link classes in the HTML as well) before outputting the adapted page to the user. I read that regex is not a good way to find those links-- so should I use a library, and if so, is html5lib good for what I'm doing?

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  • Is SHA-1 secure for password storage?

    - by Tgr
    Some people throw around remarks like "SHA-1 is broken" a lot, so I'm trying to understand what exactly that means. Let's assume I have a database of SHA-1 password hashes, and an attacker whith a state of the art SHA-1 breaking algorithm and a botnet with 100,000 machines gets access to it. (Having control over 100k home computers would mean they can do about 10^15 operations per second.) How much time would they need to find out the password of any one user? find out the password of a given user? find out the password of all users? find a way to log in as one of the users? find a way to log in as a specific user? How does that change if the passwords are salted? Does the method of salting (prefix, postfix, both, or something more complicated like xor-ing) matter? Here is my current understanding, after some googling. Please correct in the answers if I misunderstood something. If there is no salt, a rainbow attack will immediately find all passwords (except extremely long ones). If there is a sufficiently long random salt, the most effective way to find out the passwords is a brute force or dictionary attack. Neither collision nor preimage attacks are any help in finding out the actual password, so cryptographic attacks against SHA-1 are no help here. It doesn't even matter much what algorithm is used - one could even use MD5 or MD4 and the passwords would be just as safe (there is a slight difference because computing a SHA-1 hash is slower). To evaluate how safe "just as safe" is, let's assume that a single sha1 run takes 1000 operations and passwords contain uppercase, lowercase and digits (that is, 60 characters). That means the attacker can test 1015*60*60*24 / 1000 ~= 1017 potential password a day. For a brute force attack, that would mean testing all passwords up to 9 characters in 3 hours, up to 10 characters in a week, up to 11 characters in a year. (It takes 60 times as much for every additional character.) A dictionary attack is much, much faster (even an attacker with a single computer could pull it off in hours), but only finds weak passwords. To log in as a user, the attacker does not need to find out the exact password; it is enough to find a string that results in the same hash. This is called a first preimage attack. As far as I could find, there are no preimage attacks against SHA-1. (A bruteforce attack would take 2160 operations, which means our theoretical attacker would need 1030 years to pull it off. Limits of theoretical possibility are around 260 operations, at which the attack would take a few years.) There are preimage attacks against reduced versions of SHA-1 with negligible effect (for the reduced SHA-1 which uses 44 steps instead of 80, attack time is down from 2160 operations to 2157). There are collision attacks against SHA-1 which are well within theoretical possibility (the best I found brings the time down from 280 to 252), but those are useless against password hashes, even without salting. In short, storing passwords with SHA-1 seems perfectly safe. Did I miss something?

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  • What's the easiest way to sort an EF4 EntityCollection<T>?

    - by Will
    I'd love to add some sorting to an EntityCollection that is bound to an ItemsControl (in xaml). I'd also like to do it as simply as possible. It appears that this is not possible. If I wrap the collection in a "sorted" version of the collection property within the Entity I lose collection change notifications. I can't use a CollectionViewSource because the entity collection's BindingListCollectionView does not support sorting for some goddamned reason (note: I've seen the blog post with the "dirty" hack to get around this, so please don't answer with that kthx). Is there a simple (couple lines of xaml, couple lines of code, whatever) way to achieve this??

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  • NSTableView setting the sort column?

    - by overcyn
    I have a NSTableView with multiple columns. clicking each of the columns sorts by the column like in iTunes. However when the tableview first loads the rows are unsorted and no tablecolumn is highlighted or displaying the up/down indicator image. I'm wondering if theres a simple way I can programmatically set the column the table is sorted by and set the indicator image on startup. The only solution I can think of is using [NSTableView setIndicatorImage: inTableColumn:] and [NSTableView setHighlightedColumn:], but that makes it so that clicking on the header doesnt highlight the column. I would rather not have to use tableView:mouseDownInHeaderOfTableColumn: and rewrite the whole click on header to sort thing.

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  • Select newly added Row - DataGridView and BindingSource

    - by Ruben Trancoso
    I'm adding a new Row to a BindingSource that is Bound to a DataGridView source.AddNew(); After this, use BindingSource to get the newly added row is return the next row in the DataGridView when its sorted. ROW "A" ROW "B" <- myBindingSource.AddNew(); ROW "C" myBindingSource.Current gives ROW "C". (it became the selected row in the DataGridView) I need this because I want to update just the newly added row DataRowView drv = (DataRowView)myBindingSource.Current; myTableAdapter.Update(drv.Row); and not the entire table. myTableAdapter.Update(myDataSet.myTable); and also, I would like to have this newly added line selected in the DataGridView after insertion. is it possible in some way?

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  • word frequency problem

    - by davit-datuashvili
    hi in programming pearls i have meet following problem question is this:print words in decreasing frequency or as i understand probllem is this suppose there is given string array let call it s words i have taken randomly it does not matter String s[]={"cat","cat","dog","fox","cat","fox","dog","cat","fox}; and we see that string cat occurs 4 times fox 3 times and dog 2 times so result will be such cat fox dog i have following code in java mport java.util.*; public class string { public static void main(String[] args){ String s[]={"fox","cat","cat","fox","dog","cat","fox","dog","cat"}; Arrays.sort(s); int counts; int count[]=new int[s.length]; for (int i=0;i } } or i have sorted array and create count array where i write number of each word in array problem is that somehow index of integer array element and string array element is not same how to do such that print words according tu maximum elements of integer array? please help me

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  • Efficiently check string for one of several hundred possible suffixes

    - by Ghostrider
    I need to write a C/C++ function that would quickly check if string ends with one of ~1000 predefined suffixes. Specifically the string is a hostname and I need to check if it belongs to one of several hundred predefined second-level domains. This function will be called a lot so it needs to be written as efficiently as possible. Bitwise hacks etc anything goes as long as it turns out fast. Set of suffixes is predetermined at compile-time and doesn't change. I am thinking of either implementing a variation of Rabin-Karp or write a tool that would generate a function with nested ifs and switches that would be custom tailored to specific set of suffixes. Since the application in question is 64-bit to speed up comparisons I could store suffixes of up to 8 bytes in length as const sorted array and do binary search within it. Are there any other reasonable options?

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  • Is there a way to replace the Eclipse JDT's code completion list with a multi-level tree?

    - by Uri
    I know that the eclipse code completion widget can be customized to add new suggestions and even to change the order. I'm wondering whether there's a way to replace the current list format (or single-level tree, if this is a tree control) with a tree of multiple levels. Thus, for example, instead of selecting from a list of methods sorted by name, I will select from a category and then from a subcategory, and then from the items. I'm not too familiar with that part of the SDK, but I'd like to know if this is feasible. Thanks!

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  • jQuery AJAX (google PageRank)

    - by RobertPitt
    Hey guys, I need a little help.. iv'e been developing a Jqery plug-in to get the page ranks of urls on a website using XHR, The problem is when requesting the rank from google servers the page is returned no content, but if i use an inspector and get the url that was requests and go to it via my browser the pageranks are shown. so it must be something with headers but its just got me puzzled. Heres some source code but i have removed several aspects that are not needed to review. pagerank.plugin.js ( $.fn.PageRank = function(callback) { var _library = new Object(); //Creat the system library _library.parseUrl = function(a) { var b = {}; var a = a || ''; /* * parse the url to extract its parts */ if (a = a.match(/((s?ftp|https?):\/\/){1}([^\/:]+)?(:([0-9]+))?([^\?#]+)?(\?([^#]+))?(#(.+))?/)) { b.scheme = a[2] ? a[2] : "http"; b.host = a[3] ? a[3] : null; b.port = a[5] ? a[5] : null; b.path = a[6] ? a[6] : null; b.args = a[8] ? a[8] : null; b.anchor = a[10] ? a[10] : null } return b } _library.ValidUrl = function(url) { var b = true; return b = url.host === undefined ? false : url.scheme != "http" && url.scheme != "https" ? false : url.host == "localhost" ? false : true } _library.toHex = function(a){ return (a < 16 ? "0" : "") + a.toString(16) } _library.hexEncodeU32 = function(a) { } _library.generateHash = function(a) { for (var b = 16909125, c = 0; c < a.length; c++) { } return _library.hexEncodeU32(b) } var CheckPageRank = function(domain,_call) { var hash = _library.generateHash(domain); $.ajax( { url: 'http://www.google.com/search?client=navclient-auto&ch=8'+hash+'&features=Rank&q=info:' + escape(domain), async: true, dataType: 'html', ifModified:true, contentType:'', type:'GET', beforeSend:function(xhr) { xhr.setRequestHeader('Referer','http://google.com/'); //Set Referer }, success: function(content,textS,xhr){ var d = xhr.responseText.substr(9, 2).replace(/\s$/, ""); if (d == "" || isNaN(d * 1)) d = "0"; _call(d); } }); } //Return the callback $(this).each(function(){ urlsegments = _library.parseUrl($(this).attr('href')) if(_library.ValidUrl(urlsegments)) { CheckPageRank(urlsegments.host,function(rank){ alert(rank) callback(rank); }); } }); return this; //Dont break any chain. } )(jQuery); Index.html (example) <html> <head> <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.1/jquery.min.js"></script> <script type="text/javascript" src="pagerank.plugin.js"></script> <script type="text/javascript"> $(document).ready(function() { $('a').PageRank(function(pr){ alert(pr); }) }); </script> </head> <body> <a href="http://facebook.com">a</a> <a href="http://twitter.com">a</a> <div></div> </body> </html> i just cant understand why its doing this.

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  • fast algorithm implementation to sort very small set

    - by aaa
    hello. This is the problem I ran into long time ago. I thought I may ask your for your ideas. assume I have very small set of numbers (integers), 4 or 8 elements, that need to be sorted, fast. what would be the best approach/algorithm? my approach was to use the max/min functions. I guess my question pertains more to implementation, rather than type of algorithm. At this point it becomes somewhat hardware dependent , so let us assume Intel 64-bit processor with SSE3 . Thanks

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  • Sorting tree with a materialized path?

    - by Ovid
    I have a tree structure in a table and it uses materialized paths to allow me to find children quickly. However, I also need to sort the results depth-first, as one would expect with threaded forum replies. id | parent_id | matpath | created ----+-----------+---------+---------------------------- 2 | 1 | 1 | 2010-05-08 15:18:37.987544 3 | 1 | 1 | 2010-05-08 17:38:14.125377 4 | 1 | 1 | 2010-05-08 17:38:57.26743 5 | 1 | 1 | 2010-05-08 17:43:28.211708 7 | 1 | 1 | 2010-05-08 18:18:11.849735 6 | 2 | 1.2 | 2010-05-08 17:50:43.288759 9 | 5 | 1.5 | 2010-05-09 14:02:43.818646 8 | 6 | 1.2.6 | 2010-05-09 14:01:17.632695 So the final results should actually be sorted like this: id | parent_id | matpath | created ----+-----------+---------+---------------------------- 2 | 1 | 1 | 2010-05-08 15:18:37.987544 6 | 2 | 1.2 | 2010-05-08 17:50:43.288759 8 | 6 | 1.2.6 | 2010-05-09 14:01:17.632695 3 | 1 | 1 | 2010-05-08 17:38:14.125377 4 | 1 | 1 | 2010-05-08 17:38:57.26743 5 | 1 | 1 | 2010-05-08 17:43:28.211708 9 | 5 | 1.5 | 2010-05-09 14:02:43.818646 7 | 1 | 1 | 2010-05-08 18:18:11.849735 How would I work that out? Can I do that in straight SQL (this is PostgreSQL 8.4) or should additional information be added to this table?

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  • Is this a violation of the single responsiblity principle?

    - by L. Moser
    I have the following method and interface: public object ProcessRules(List<IRule> rules) { foreach(IRule rule in rules) { if(EvaluateExpression(rule.Exp) == true) return rule.Result; } //Some error handling here for not hitting any rules } public interface IRule { Expression Exp; Object Result; int Precedence; } Because rules have a precedence, they should actually never be processed out of order. This leads me with (I think) three solutions: Sort rules before passing them into the evaluator. Change the parameter type to something that enforces a sort order. Sort within the evaluator. I like option 3 because it always ensures that it is sorted and I like option 1 because it seems more cohesive. And option 2 seems like a good compromise. Is a scenario like this context specific/subjective, or is there really a best practice to be applied here?

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  • Custom Sorting on Custom Field in Django

    - by RotaJota
    In my app, I have defined a custom field to represent a physical quantity using the quantities package. class AmountField(models.CharField): def __init__(self, *args, **kwargs): ... def to_python(self, value): create_quantities_value(value) Essentially the way it works is it extends CharField to store the value as a string in the database "12 min" and represents it as a quantities object when using the field in a model array(12) * min Then in a model it is used as such: class MyModel(models.Model): group = models.CharField() amount = AmountField() class Meta: ordering = ['group', 'amount'] My issue is that these fields do not seem to sort by the quantity, but instead by the string. So if I have some objects that contain something like {"group":"A", "amount":"12 min"} {"group":"A", "amount":"20 min"} {"group":"A", "amount":"2 min"} {"group":"B", "amount":"20 min"} {"group":"B", "amount":"1 hr"} they end up sorted something like this: >>> MyModel.objects.all() [{A, 12 min}, {A, 2 min}, {A, 20 min}, {B, 1 hr}, {B, 20 min}] essentially alphabetical order. Can I give my custom AmountField a comparison function so that it will compare by the python value instead of the DB value?

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  • Setting AcceptButton to None still closes the form on ENTER.

    - by Vilx-
    I have a MDI windows forms application and my child forms mostly have "OK" and "Cancel" buttons. However I do not want them to be activated with ENTER/ESC keys to prevent accidental saves/aborts. So, the form has both AcceptButton and CancelButton set to none. The ESC button indeed does nothing, but the ENTER button still closes the form by "clicking" on the first button found, sorted by TabOrder. Why is this so? Must I really start doing workarounds and catching the ENTER key?

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  • PyML 0.7.2 - How to prevent accuracy from dropping after storing/loading a classifier?

    - by Michael Aaron Safyan
    This is a followup from "Save PyML.classifiers.multi.OneAgainstRest(SVM()) object?". The solution to that question was close, but not quite right, (the SparseDataSet is broken, so attempting to save/load with that dataset container type will fail, no matter what. Also, PyML is inconsistent in terms of whether labels should be numbers or strings... it turns out that the oneAgainstRest function is actually not good enough, because the labels need to be strings and simultaneously convertible to floats, because there are places where it is assumed to be a string and elsewhere converted to float) and so after a great deal of hacking and such I was finally able to figure out a way to save and load my multi-class classifier without it blowing up with an error.... however, although it is no longer giving me an error message, it is still not quite right as the accuracy of the classifier drops significantly when it is saved and then reloaded (so I'm still missing a piece of the puzzle). I am currently using the following custom mutli-class classifier for training, saving, and loading: class SVM(object): def __init__(self,features_or_filename,labels=None,kernel=None): if isinstance(features_or_filename,str): filename=features_or_filename; if labels!=None: raise ValueError,"Labels must be None if loading from a file."; with open(os.path.join(filename,"uniquelabels.list"),"rb") as uniquelabelsfile: self.uniquelabels=sorted(list(set(pickle.load(uniquelabelsfile)))); self.labeltoindex={}; for idx,label in enumerate(self.uniquelabels): self.labeltoindex[label]=idx; self.classifiers=[]; for classidx, classname in enumerate(self.uniquelabels): self.classifiers.append(PyML.classifiers.svm.loadSVM(os.path.join(filename,str(classname)+".pyml.svm"),datasetClass = PyML.VectorDataSet)); else: features=features_or_filename; if labels==None: raise ValueError,"Labels must not be None when training."; self.uniquelabels=sorted(list(set(labels))); self.labeltoindex={}; for idx,label in enumerate(self.uniquelabels): self.labeltoindex[label]=idx; points = [[float(xij) for xij in xi] for xi in features]; self.classifiers=[PyML.SVM(kernel) for label in self.uniquelabels]; for i in xrange(len(self.uniquelabels)): currentlabel=self.uniquelabels[i]; currentlabels=['+1' if k==currentlabel else '-1' for k in labels]; currentdataset=PyML.VectorDataSet(points,L=currentlabels,positiveClass='+1'); self.classifiers[i].train(currentdataset,saveSpace=False); def accuracy(self,pts,labels): logger=logging.getLogger("ml"); correct=0; total=0; classindexes=[self.labeltoindex[label] for label in labels]; h=self.hypotheses(pts); for idx in xrange(len(pts)): if h[idx]==classindexes[idx]: logger.info("RIGHT: Actual \"%s\" == Predicted \"%s\"" %(self.uniquelabels[ classindexes[idx] ], self.uniquelabels[ h[idx] ])); correct+=1; else: logger.info("WRONG: Actual \"%s\" != Predicted \"%s\"" %(self.uniquelabels[ classindexes[idx] ], self.uniquelabels[ h[idx] ])) total+=1; return float(correct)/float(total); def prediction(self,pt): h=self.hypothesis(pt); if h!=None: return self.uniquelabels[h]; return h; def predictions(self,pts): h=self.hypotheses(self,pts); return [self.uniquelabels[x] if x!=None else None for x in h]; def hypothesis(self,pt): bestvalue=None; bestclass=None; dataset=PyML.VectorDataSet([pt]); for classidx, classifier in enumerate(self.classifiers): val=classifier.decisionFunc(dataset,0); if (bestvalue==None) or (val>bestvalue): bestvalue=val; bestclass=classidx; return bestclass; def hypotheses(self,pts): bestvalues=[None for pt in pts]; bestclasses=[None for pt in pts]; dataset=PyML.VectorDataSet(pts); for classidx, classifier in enumerate(self.classifiers): for ptidx in xrange(len(pts)): val=classifier.decisionFunc(dataset,ptidx); if (bestvalues[ptidx]==None) or (val>bestvalues[ptidx]): bestvalues[ptidx]=val; bestclasses[ptidx]=classidx; return bestclasses; def save(self,filename): if not os.path.exists(filename): os.makedirs(filename); with open(os.path.join(filename,"uniquelabels.list"),"wb") as uniquelabelsfile: pickle.dump(self.uniquelabels,uniquelabelsfile,pickle.HIGHEST_PROTOCOL); for classidx, classname in enumerate(self.uniquelabels): self.classifiers[classidx].save(os.path.join(filename,str(classname)+".pyml.svm")); I am using the latest version of PyML (0.7.2, although PyML.__version__ is 0.7.0). When I construct the classifier with a training dataset, the reported accuracy is ~0.87. When I then save it and reload it, the accuracy is less than 0.001. So, there is something here that I am clearly not persisting correctly, although what that may be is completely non-obvious to me. Would you happen to know what that is?

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  • distinct in Xpath ?

    - by Antoine
    Hi, I have this XML file, from which I'd like to count the number of users referenced in it. But they can appear in more than one category, and I'd like these duplicates not to be taken into account. In the example below, the query should return 3 and not 4. Is there a way in XPath to do so? Users are not sorted at all. <list> <group name='QA'> <user name='name1'>name1@email</user> <user name='name2'>name2@email</user> </group> <group name='DEV'> <user name='name3'>name3@email</user> <user name='name2'>name2@email</user> </group> </list>

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  • Customized sorting on DataTable in C#?

    - by Steve
    This is a C# Winform question. I have a DataGridView which is bounded to a DataTable. I construct the DataTable myself, which several DataColumn instances. When the DataTable is bound to the DataGridView, by default, every column is sortable by clicking the headers of the DataGridView. But the sorting behavior is something "by default". It seems that it is sorted by string. This is true even if I put this as my code: DataColumn dc = new DataColumn("MyObjectColumn", typeof(MyObject)); And MyObject has overriden ToString() and has implemented the IComparable interface. That means even if I have told the DataTable how to sort the special column with the implementation of IComparable interface, DataGridView still doesn't do it the way I expect. So how can I let DataTable sort data in the way I want? Thanks for the answers.

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  • problem in leigeber's sorting

    - by developer
    iam using leigeber's sorting javascript to sort my data on my page......i took the js from here :- leigeber's sorting javascript Now this is shwoing highlighted sorted column and all and its all perfect.Now iam having some negative and some positive values in my data and i want to show those negative data in red color and positive in green.This whole sorting thing is using js and css to do the highlighting and sorting.Iam a bit confused now and cant make it out that how i can assign red color to the negative ones and green to the positive ones as js is returning the data as an object i.e. a complete row and i cant make 1 column's data red or green.Will it be done by js itself or with the help of stylesheet to find -ves and +ves.Im totally lost and dont know how to do it.Please help!!!! this is an example of hte data iam using this whole sorting thing on:- -Name- -Price- -loss- -Pts- abc 361.15 -5.68 -21.75 abc2 1072.35 -5.24 -59.25 abc3 512.35 5.24 28.35 abc4 335.2 -5.02 -17.7 abc5 318.6 5.01 -16.8 abc6 76.15 -4.15 3.3

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  • Order by nullable property simultaneously with ordering by not nullable property in HQL

    - by Episodex
    Hi, I have a table called Users in my database. Let's assume that User has only 3 properties int ID; string? Name; string Login; If user doesn't specify his name then Login is displayed. Otherwise Name is displayed. I wan't to get list of all users sorted by what is displayed. So if user specified Name, it is taken into consideration while sorting, otherwise his position on the list should be determined by Login. Eventually whole list should be ordered alphabetically. I hope I made myself clear... Is that possible to do in HQL?

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  • Multiple range product in Python

    - by Tyr
    Is there a better way to do this: perms = product(range(1,7),range(1,7),range(1,7)) so that I can choose how many ranges I use? I want it to be equivalent to this, but scalable. def dice(num) if num == 1: perms = ((i,) for i in range(1,7)) elif num == 2: perms = product(range(1,7),range(1,7)) elif num == 3: perms = product(range(1,7),range(1,7),range(1,7)) #... and so on but I know there has to be a better way. I'm using it for counting dice outcomes. The actual code def dice(selection= lambda d: d[2]): perms = itertools.product(range(1,7),range(1,7),range(1,7)) return collections.Counter(((selection(sorted(i)) for i in perms))) where I can call it with a variety of selectors, like sum(d[0:2]) for the sum of the lowest 2 dice or d[1] to get the middle dice.

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  • Overriding Object.Equals() instance method in C#; now Code Analysis / FxCop warning CA2218: "should

    - by Chris W. Rea
    I've got a complex class in my C# project on which I want to be able to do equality tests. It is not a trivial class; it contains a variety of scalar properties as well as references to other objects and collections (e.g. IDictionary). For what it's worth, my class is sealed. To enable a performance optimization elsewhere in my system (an optimization that avoids a costly network round-trip), I need to be able to compare instances of these objects to each other for equality – other than the built-in reference equality – and so I'm overriding the Object.Equals() instance method. However, now that I've done that, Visual Studio 2008's Code Analysis a.k.a. FxCop, which I keep enabled by default, is raising the following warning: warning : CA2218 : Microsoft.Usage : Since 'MySuperDuperClass' redefines Equals, it should also redefine GetHashCode. I think I understand the rationale for this warning: If I am going to be using such objects as the key in a collection, the hash code is important. i.e. see this question. However, I am not going to be using these objects as the key in a collection. Ever. Feeling justified to suppress the warning, I looked up code CA2218 in the MSDN documentation to get the full name of the warning so I could apply a SuppressMessage attribute to my class as follows: [SuppressMessage("Microsoft.Naming", "CA2218:OverrideGetHashCodeOnOverridingEquals", Justification="This class is not to be used as key in a hashtable.")] However, while reading further, I noticed the following: How to Fix Violations To fix a violation of this rule, provide an implementation of GetHashCode. For a pair of objects of the same type, you must ensure that the implementation returns the same value if your implementation of Equals returns true for the pair. When to Suppress Warnings ----- Do not suppress a warning from this rule. [arrow & emphasis mine] So, I'd like to know: Why shouldn't I suppress this warning as I was planning to? Doesn't my case warrant suppression? I don't want to code up an implementation of GetHashCode() for this object that will never get called, since my object will never be the key in a collection. If I wanted to be pedantic, instead of suppressing, would it be more reasonable for me to override GetHashCode() with an implementation that throws a NotImplementedException? Update: I just looked this subject up again in Bill Wagner's good book Effective C#, and he states in "Item 10: Understand the Pitfalls of GetHashCode()": If you're defining a type that won't ever be used as the key in a container, this won't matter. Types that represent window controls, web page controls, or database connections are unlikely to be used as keys in a collection. In those cases, do nothing. All reference types will have a hash code that is correct, even if it is very inefficient. [...] In most types that you create, the best approach is to avoid the existence of GetHashCode() entirely. ... that's where I originally got this idea that I need not be concerned about GetHashCode() always.

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  • How to merge two tables based on common column and sort the results by date

    - by techiepark
    Hello friends, I have two mysql tables and i want to merge the results of these two tables based on the common column rev_id. The merged results should be sorted by the date of two tables. Please help me. CREATE TABLE `reply` ( `id` int(3) NOT NULL auto_increment, `name` varchar(25) NOT NULL default '', `member_id` varchar(45) NOT NULL, `rev_id` int(3) NOT NULL default '0', `description` text, `post_date` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP, `flag` char(2) NOT NULL default 'N', PRIMARY KEY (`id`), KEY `member_id` (`member_id`) ) ENGINE=MyISAM; CREATE TABLE `comment` ( `com_id` int(8) NOT NULL auto_increment, `rev_id` int(5) NOT NULL default '0', `member_id` varchar(50) NOT NULL, `comm_desc` text NOT NULL, `date_created` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP, PRIMARY KEY (`com_id`), KEY `member_id` (`member_id`) ) ENGINE=MyISAM;

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  • Algorithm: efficient way to remove duplicate integers from an array

    - by ejel
    I got this problem from an interview with Microsoft. Given an array of random integers, write an algorithm in C that removes duplicated numbers and return the unique numbers in the original array. E.g Input: {4, 8, 4, 1, 1, 2, 9} Output: {4, 8, 1, 2, 9, ?, ?} One caveat is that the expected algorithm should not required the array to be sorted first. And when an element has been removed, the following elements must be shifted forward as well. Anyway, value of elements at the tail of the array where elements were shifted forward are negligible. Update: The result must be returned in the original array and helper data structure (e.g. hashtable) should not be used. However, I guess order preservation is not necessary. Update2: For those who wonder why these impractical constraints, this was an interview question and all these constraints are discussed during the thinking process to see how I can come up with different ideas.

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  • jquery ui sortable serialize from children

    - by FFish
    I want to send an Array with image paths and captions to a PHP script after I sorted the images. I can do 'serialize' or 'toArray' on the lists, but how to get the attributes from the img tag? <ul class="gallery"> <li id="li-1"> <img src="tn/001.jpg" alt="first caption" /> </li> <li mycaption="some caption" id="li-2"> <img src="tn/002.jpg" alt="second caption with éèçà international chars" /> </li> </ul> $(".gallery").sortable({ update : function() { serial = $('.gallery').sortable('serialize'); alert(serial); /* $.ajax({ url: "sort.php", type: "post", data: serial, error: function() {alert("theres an error with AJAX");} }); */ } });

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