Search Results

Search found 34758 results on 1391 pages for 'linear linked list invert'.

Page 822/1391 | < Previous Page | 818 819 820 821 822 823 824 825 826 827 828 829  | Next Page >

  • How do I restrict foreign keys choices to related objects only in django

    - by Jeff Mc
    I have a two way foreign relation similar to the following class Parent(models.Model): name = models.CharField(max_length=255) favoritechild = models.ForeignKey("Child", blank=True, null=True) class Child(models.Model): name = models.CharField(max_length=255) myparent = models.ForeignKey(Parent) How do I restrict the choices for Parent.favoritechild to only children whose parent is itself? I tried class Parent(models.Model): name = models.CharField(max_length=255) favoritechild = models.ForeignKey("Child", blank=True, null=True, limit_choices_to = {"myparent": "self"}) but that causes the admin interface to not list any children.

    Read the article

  • Django left join m2m field.

    - by duder
    Here's my Model: class User(models.Model): pass class Item(models.Model): pass class ItemVote(models.Model): user = models.ForeignKey(User) item = models.ForeignKey(Item) vote = models.BooleanField() I want to retrieve a list of Items, and I want to know if the current user has voted for each Item. How do I alter my query object so that it will generate sql similar to: SELECT ... FROM items LEFT OUTER JOIN item_votes ON (item_votes.user_id = ? AND item_votes.item_id = items.id)

    Read the article

  • Python/YACC Lexer: Token priority?

    - by Rosarch
    I'm trying to use reserved words in my grammar: reserved = { 'if' : 'IF', 'then' : 'THEN', 'else' : 'ELSE', 'while' : 'WHILE', } tokens = [ 'DEPT_CODE', 'COURSE_NUMBER', 'OR_CONJ', 'ID', ] + list(reserved.values()) t_DEPT_CODE = r'[A-Z]{2,}' t_COURSE_NUMBER = r'[0-9]{4}' t_OR_CONJ = r'or' t_ignore = ' \t' def t_ID(t): r'[a-zA-Z_][a-zA-Z_0-9]*' if t.value in reserved.values(): t.type = reserved[t.value] return t return None However, the t_ID rule somehow swallows up DEPT_CODE and OR_CONJ. How can I get around this? I'd like those two to take higher precedence than the reserved words.

    Read the article

  • Linq qurery with multiple where's

    - by Dan
    I am trying the to query my Status Update repository using the following var result = (from s in _dataContext.StatusUpdates where s.Username == "friend1" && s.Username == "friend2" etc... select s).ToList(); Insead of using s.Username == "friendN" continously is there anyway I can pass a list or array or something like that rather that specifying each one, or can i use a foreach loop in the middle of the query. Thanks

    Read the article

  • Does my TPL partitioner cause a deadlock?

    - by Scott Chamberlain
    I am starting to write my first parallel applications. This partitioner will enumerate over a IDataReader pulling chunkSize records at a time from the data-source. protected class DataSourcePartitioner<object[]> : System.Collections.Concurrent.Partitioner<object[]> { private readonly System.Data.IDataReader _Input; private readonly int _ChunkSize; public DataSourcePartitioner(System.Data.IDataReader input, int chunkSize = 10000) : base() { if (chunkSize < 1) throw new ArgumentOutOfRangeException("chunkSize"); _Input = input; _ChunkSize = chunkSize; } public override bool SupportsDynamicPartitions { get { return true; } } public override IList<IEnumerator<object[]>> GetPartitions(int partitionCount) { var dynamicPartitions = GetDynamicPartitions(); var partitions = new IEnumerator<object[]>[partitionCount]; for (int i = 0; i < partitionCount; i++) { partitions[i] = dynamicPartitions.GetEnumerator(); } return partitions; } public override IEnumerable<object[]> GetDynamicPartitions() { return new ListDynamicPartitions(_Input, _ChunkSize); } private class ListDynamicPartitions : IEnumerable<object[]> { private System.Data.IDataReader _Input; int _ChunkSize; private object _ChunkLock = new object(); public ListDynamicPartitions(System.Data.IDataReader input, int chunkSize) { _Input = input; _ChunkSize = chunkSize; } public IEnumerator<object[]> GetEnumerator() { while (true) { List<object[]> chunk = new List<object[]>(_ChunkSize); lock(_Input) { for (int i = 0; i < _ChunkSize; ++i) { if (!_Input.Read()) break; var values = new object[_Input.FieldCount]; _Input.GetValues(values); chunk.Add(values); } if (chunk.Count == 0) yield break; } var chunkEnumerator = chunk.GetEnumerator(); lock(_ChunkLock) //Will this cause a deadlock? { while (chunkEnumerator.MoveNext()) { yield return chunkEnumerator.Current; } } } } IEnumerator IEnumerable.GetEnumerator() { return ((IEnumerable<object[]>)this).GetEnumerator(); } } } I wanted IEnumerable object it passed back to be thread safe (the .Net example was so I am assuming PLINQ and TPL could need it) will the lock on _ChunkLock near the bottom help provide thread safety or will it cause a deadlock? From the documentation I could not tell if the lock would be released on the yeld return. Also if there is built in functionality to .net that will do what I am trying to do I would much rather use that. And if you find any other problems with the code I would appreciate it.

    Read the article

  • Summary of changes for each API level?

    - by MisterSquonk
    As the title says, are there any sources (web pages etc) of summarised changes at each API level? I have an app which I've put out to a small group of beta testers and I already fell foul of Environment.getExternalFilesDir(), which I hadn't noticed was introduced in API Level 8, when a couple of the guys tried it on Android v2.1 devices. The majority of my code should be pretty generic but it would be useful if I could find a condensed/summarised list/table or similar that I can quickly glance over.

    Read the article

  • Excel VBA / SQL Union

    - by Edge
    Hi, I am trying to Join 2 seperate columns from 2 different sheets to make a longer column from which i can then use a Vlookup from. Sheet1 A, B, C, D, E, F, G Sheet2 A, B, C, D, E, F, G I want to Join(Union) Columns B from sheet1 and C from sheet2 together and find the Distinct values of the new list. I have been working on this for weeks. Thanks

    Read the article

  • What IoC Containers Support Silverlight?

    - by Matt Casto
    I'm looking for a list of IoC Containers that support Silverlight. I know that Unity and Ninject work with Silverlight, but I haven't found any information that suggests that other well known containers, like StructureMap, Castle Windsor or Autofac, support Silverlight. Has anyone used these, or other, containers or compared them with the Silverlight platform in mind?

    Read the article

  • Which XML library for what purposes?

    - by John Mee
    A search for "python" and "xml" returns a variety of libraries for combining the two. This list probably faulty: xml.dom xml.etree xml.sax xml.parsers.expat PyXML beautifulsoup? HTMLParser htmllib sgmllib Be nice if someone can offer a quick summary of when to use which, and why.

    Read the article

  • Can sorting Japanese kanji words be done programatically?

    - by Mason
    I've recently discovered, to my astonishment (having never really thought about it before), machine-sorting Japanese proper nouns is apparently not possible. I work on an application that must allow the user to select a hospital from a 3-menu interface. The first menu is Prefecture, the second is City Name, and the third is Hospital. Each menu should be sorted, as you might expect, so the user can find what they want in the menu. Let me outline what I have found, as preamble to my question: The expected sort order for Japanese words is based on their pronunciation. Kanji do not have an inherent order (there are tens of thousands of Kanji in use), but the Japanese phonetic syllabaries do have an order: ???????????????????... and on for the fifty traditional distinct sounds (a few of which are obsolete in modern Japanese). This sort order is called ???? (gojuu on jun , or '50-sound order'). Therefore, Kanji words should be sorted in the same order as they would be if they were written in hiragana. (You can represent any kanji word in phonetic hiragana in Japanese.) The kicker: there is no canonical way to determine the pronunciation of a given word written in kanji. You never know. Some kanji have ten or more different pronunciations, depending on the word. Many common words are in the dictionary, and I could probably hack together a way to look them up from one of the free dictionary databases, but proper nouns (e.g. hospital names) are not in the dictionary. So, in my application, I have a list of every prefecture, city, and hospital in Japan. In order to sort these lists, which is a requirement, I need a matching list of each of these names in phonetic form (kana). I can't come up with anything other than paying somebody fluent in Japanese (I'm only so-so) to manually transcribe them. Before I do so though: Is it possible that I am totally high on fire, and there actually is some way to do this sorting without creating my own mappings of kanji words to phonetic readings, that I have somehow overlooked? Is there a publicly available mapping of prefecture/city names, from the government or something? That would reduce the manual mapping I'd need to do to only hospital names. Does anybody have any other advice on how to approach this problem? Any programming language is fine--I'm working with Ruby on Rails but I would be delighted if I could just write a program that would take the kanji input (say 40,000 proper nouns) and then output the phonetic representations as data that I could import into my Rails app. ??????????

    Read the article

  • How to write a contains statement to match a member of a class?

    - by afuzzyllama
    If I have the following structure: Public Class UserData Public ID As String Public Name As String End Class How can I select it in a conditional like this? Dim myUsers As New List(Of UserData) If myUsers.Contains(.ID = "1") = True Then ... I know that myUsers.Contains(.ID = "1") is totally wrong, but I am curious how to do something like that? Is it possible? Is this a job for LINQ?

    Read the article

  • Extract new image dimensions from timthumb

    - by jonthoughtit
    I'm using timthumb to resize my images because it scales them nicely if I only enter one of the dimensions. However I want to know if it's possible to extract the new resized image's dimensions so that I can add that dynamically to the img tag attributes. I tried this with no luck: $fullpath = '/lib/timthumb.php?src='.$image.'&w=100'; $my_image = array_values(getimagesize($fullpath)); list($width, $height, $type, $attr) = $my_image; Any ideas?

    Read the article

  • How to export shell variable within perl script

    - by lamcro
    I have a shell script, with a list of shell variables, which is executed before entering a programming environment. I want to use a perl script to enter the programming environment: system("environment_defaults.sh"); system("obe"); but I when I enter the environment the variables are not set.

    Read the article

  • Linking two models in a multi-model form

    - by Elliot
    Hey Guys, I have a nested multimodel form right now, using Users and Profiles. Users has_one profile, and Profile belongs_to Users. When the form is submitted, a new user is created, and a new profile is created, but they are not linked (this is the first obvious issue). The user's model has a profile_id row, and the profile's model has a user_id row. Here is the code for the form: <%= form_for(@user, :url => teams_path) do |f| %> <p><%= f.label :email %><br /> <%= f.text_field :email %></p> <p><%= f.label :password %><br /> <%= f.password_field :password %></p> <p><%= f.label :password_confirmation %><br /> <%= f.password_field :password_confirmation %></p> <%= f.hidden_field :role_id, :value => @role.id %></p> <%= f.hidden_field :company_id, :value => current_user.company_id %></p> <%= fields_for @user.profile do |profile_fields| %> <div class="field"> <%= profile_fields.label :first_name %><br /> <%= profile_fields.text_field :first_name %> </div> <div class="field"> <%= profile_fields.label :last_name %><br /> <%= profile_fields.text_field :last_name %> </div> <% end %> <p><%= f.submit "Sign up" %></p> <% end %> A second issue, is even though the username, and password are successfully created through the form for the user model, the hidden fields (role_id & company_id - which are also links to other models) are not created (even though they are part of the model) - the values are successfully shown in the HTML for those fields however. Any help would be great!

    Read the article

  • 2 roles, admin and user. Is using anything other than basic http auth overkill?

    - by juststarting
    I'm building my first website with rails,it consists of a blog, a few static pages and a photo gallery. The admin section has namespaced controllers. I also want to create a mailing list, collecting contact info, (maybe a spree store in the future too.) Should I just use basic http authentication and check if the user is admin? Or is a plugin like authlogic better, then define user roles even though there would only be two; admin and user?

    Read the article

  • How can you represent a .NET DataType in a UML Diagram

    - by Blake Blackwell
    I am new to UML diagramming, but I'm trying to learn the ropes. Using a tool such as Visio or AgroUML how would you represent a .NET Datatype in your diagram? Two examples that I would like to do: DataTable List<MyObject> The only method I see right now is creating a class that represents a datatable. As far as representing collections, I can't find any method to do that. Thanks!

    Read the article

  • Can this django query be improved?

    - by Hobhouse
    Given a model structure like this: class Book(models.Model): user = models.ForeignKey(User) class Readingdate(models.Model): book = models.ForeignKey(Book) date = models.DateField() One book may have several readingdates. How do I list books having at least one readingdate within a specific year? I can do this: from_date = datetime.date(2010,1,1) to_date = datetime.date(2010,12,31) book_ids = Readingdate.objects\ .filter(date__range=(from_date,to_date))\ .values_list('book_id', flat=True) books_read_2010 = Book.objects.filter(id__in=book_ids) Is it possible to do this with one queryset, or is this the best way?

    Read the article

  • Ruby Nokogiri uninitialized constant

    - by donald
    `<main>': uninitialized constant Object::Nakogiri (NameError) I get that message when trying to run a simple code (ruby test.rb): require 'rubygems' require 'nokogiri' require 'open-uri' url = "http://www.walmart.com/cp/Baby-Days/1035659?povid=cat14503-env172199-module122910-lLinksptBABY" doc = Nakogiri::HTML(open(url)) puts doc.at_css("title").text I have the gem installed: ~/Code $ gem list --local | grep nokogiri nokogiri (1.4.4, 1.4.3.1)

    Read the article

  • WPF MVVM Cancel Edit

    - by terkri
    How can I implement cancelation of editing an object using MVVM. For example: I have a list of customers. I choose one customer an click the button "Edit", a dialog window(DataContext is binded to CustomerViewModel) opens and I start editing customer's fields. And then I decide to cancel editing, but the fields of the customer have been already changed, so how can I return a customer to its previous state in MVVM?

    Read the article

< Previous Page | 818 819 820 821 822 823 824 825 826 827 828 829  | Next Page >