Try adding the `()` after `all`: `myStuff.things.all()`

Like Abid A already answered, you are missing brackets ()

    for t in myStuff.things.all():
        print t.myStuffs.all()


ManyToManyField seems to have a different kind of Manager than your basic Django class.  Looking at the source here, https://github.com/django/django/blob/master/django/db/models/fields/related_descriptors.py#L821, it seems you are looking for the related_val field which appears to contain the tuple of related objects references.

Is it possible to show row number in the row header of a `DataGridView`?        

I&#39;m trying with this code, but it doesn&#39;t work:

        
        private void setRowNumber(DataGridView dgv)
        {
            foreach (DataGridViewRow row in dgv.Rows)
            {
                row.HeaderCell.Value = row.Index + 1;
            }
        }
Do I have to set some `DataGridView` property?

Show row number in row header of a DataGridView

In this application that I&#39;m trying to make, I use push notifications. This part works just fine. When I send a notification I also add a badge to the app icon. The problem is when I lunch the application it should disappear again, but it does not.

    -(IBAction)Push{
    	
        NSMutableDictionary *data = [NSMutableDictionary dictionary];
        
        [data setObject:@&quot;Numfeud: Troels made a move!&quot; forKey:@&quot;alert&quot;];
        
        [data setObject:[NSNumber numberWithInt:1] forKey:@&quot;badge&quot;];
            
        [data setObject:@&quot;bar&quot; forKey:@&quot;foo&quot;];
        
        [PFPush sendPushDataToChannelInBackground:@&quot;GameChannel2&quot; withData:data];
    }

In the `application didFinishLaunchingWithOptions` I try to set badge to 0 in this way:

    [UIApplication sharedApplication].applicationIconBadgeNumber = 0;

How can I clear the application icon badge?


Removing badge from iOS app icon

A simple question and yet I can&#39;t find an answer for it.

I have a model with a ManyToMany field:

    class Stuff(models.Model):
      things = models.ManyToManyField(Thing)

then in a different function I want to do this:

    myStuff = Stuff.objects.get(id=1)
    for t in myStuff.things.all:
      # ...

But that is giving me:

    TypeError: &#39;instancemethod&#39; object is not iterable

How can I iterate over a manyToManyField ?



How can I iterate over ManyToManyField?

A simple question and yet I can't find an answer for it.
I have a model with a ManyToMany field:
<pre><code class="hljs language-arduino">class Stuff(models.Model):
 things = models.ManyToManyField(Thing)
</code></pre>
then in a different function I want to do this:
<pre><code class="hljs language-ini">myStuff = Stuff.objects.get(id=1)
for t in myStuff.things.all:
 # ...
</code></pre>
But that is giving me:
<pre><code class="hljs language-php">TypeError: 'instancemethod' object is not iterable
</code></pre>
How can I iterate over a manyToManyField ?

Say I have a multiple inheritance scenario:

    class A(object):
        # code for A here

    class B(object):
        # code for B here

    class C(A, B):
        def __init__(self):
            # What&#39;s the right code to write here to ensure 
            # A.__init__ and B.__init__ get called?

There&#39;s two typical approaches to writing `C`&#39;s `__init__`:

 1. (old-style) `ParentClass.__init__(self)`
 2. (newer-style) `super(DerivedClass, self).__init__()`

However, in either case, if the parent classes (`A` and `B`) [don&#39;t follow the same convention, then the code will not work correctly](http://fuhm.org/super-harmful/) (some may be missed, or get called multiple times).

So what&#39;s the correct way again?  It&#39;s easy to say &quot;just be consistent, follow one or the other&quot;, but if `A` or `B` are from a 3rd party library, what then?  Is there an approach that can ensure that all parent class constructors get called (and in the correct order, and only once)?

Edit: to see what I mean, if I do:

    class A(object):
        def __init__(self):
            print(&quot;Entering A&quot;)
            super(A, self).__init__()
            print(&quot;Leaving A&quot;)
            
    class B(object):
        def __init__(self):
            print(&quot;Entering B&quot;)
            super(B, self).__init__()
            print(&quot;Leaving B&quot;)
    
    class C(A, B):
        def __init__(self):
            print(&quot;Entering C&quot;)
            A.__init__(self)
            B.__init__(self)
            print(&quot;Leaving C&quot;)

Then I get:

    Entering C
    Entering A
    Entering B
    Leaving B
    Leaving A
    Entering B
    Leaving B
    Leaving C

Note that `B`&#39;s init gets called twice.  If I do: 

    class A(object):
        def __init__(self):
            print(&quot;Entering A&quot;)
            print(&quot;Leaving A&quot;)
            
    class B(object):
        def __init__(self):
            print(&quot;Entering B&quot;)
            super(B, self).__init__()
            print(&quot;Leaving B&quot;)
    
    class C(A, B):
        def __init__(self):
            print(&quot;Entering C&quot;)
            super(C, self).__init__()
            print(&quot;Leaving C&quot;)

Then I get: 

    Entering C
    Entering A
    Leaving A
    Leaving C

Note that `B`&#39;s init never gets called.  So it seems that unless I know/control the init&#39;s of the classes I inherit from (`A` and `B`) I cannot make a safe choice for the class I&#39;m writing (`C`).

Calling parent class __init__ with multiple inheritance, what&#39;s the right way?

I want to skip the first 17 lines while reading a text file.

        
Let&#39;s say the file looks like:

    0
    0
    0
    0
    0
    0
    0
    0
    0
    0
    0
    0
    0
    0
    0
    0
    0
    good stuff

I just want the good stuff. What I&#39;m doing is a lot more complicated, but this is the part I&#39;m having trouble with.

Skip first couple of lines while reading lines in Python file

I recently started a Django project and I quickly realized that virtualenv will be really useful for many reasons. I set up the virtualenv and my project, but now I wonder what file I should add to my source control (in my case, Mercurial). Should I add all the files under the venv folder? How do I make sure a colleague can clone and get started to work immediately withou having to setup the env again?

Virtualenv and source version control

What&#39;s the best way to have a here document, without newlines at the top and bottom?  For example:

    print &#39;&#39;&#39;
    dog
    cat
    &#39;&#39;&#39;

will have newlines at the top and bottom, and to get rid of them I have to do this:

    print &#39;&#39;&#39;dog
    cat&#39;&#39;&#39;

which I find to be much less readable.

Python here document without newlines at top and bottom

How would I use python to convert an IP address that comes as a `str` to a decimal number and vice versa? 

For example, for the IP `186.99.109.000 &lt;type&#39;str&#39;&gt;`, I would like to have a decimal or binary form that is easy to store in a database, and then retrieve it.

Convert an IP string to a number and vice versa

I have been trying to import Database through phpMyAdmin. My database file is `a.sql` and it&#39;s size is 1.2 GB 
I am trying to import this on local and phpMyAdmin is saying:

&gt; You probably tried to upload too large file. Please refer to documentation for ways to workaround this limit.

Please help I really need this to work.

Can&#39;t import database through phpmyadmin file size too large

I have few sqlite database files. I want to know the database file version i.e if the database was created with sqlite2 or sqlite3 or any other main/sub version (not the sqlite library or driver or user_version or schema_version).

How to find SQLITE database file version

The common method to store images in a database is to convert the image to `base64` data before storing the data. This process will increase the size by 33%. Alternatively it is possible to directly store the image as a `BLOB`; for example:

    $image = new Imagick(&quot;image.jpg&quot;);
    $data = $image-&gt;getImageBlob();
    $data = $mysqli-&gt;real_escape_string($data);
    $mysqli-&gt;query(&quot;INSERT INTO images (data) VALUES (&#39;$data&#39;)&quot;);

and then display the image with

    &lt;img src=&quot;data:image/jpeg;base64,&#39; .  base64_encode($data)  . &#39;&quot; /&gt;

With the latter method, we save 1/3 storage space. Why is it more common to store images as `base64` in MySQL databases?

**UPDATE:** There are many debates about advantages and disadvantages of storing images in databases, and most people believe it is not a practical approach. Anyway, here I assume we store image in database, and discussing the best method to do so.

Storing image in database directly or as base64 data?

I believe the title is self-explanatory. How do you create the table structure in  PostgreSQL to make a many-to-many relationship.

My example:

    Product(name, price);
    Bill(name, date, Products);

How to implement a many-to-many relationship in PostgreSQL?

I have a dataset of 1 minute data of 1000 stocks since 1998, that total around `(2012-1998)*(365*24*60)*1000 = 7.3 Billion` rows.

Most (99.9%) of the time I will perform only **read** requests.

What is the best way to store this data in a db?

 - 1 big table with 7.3B rows?
 - 1000 tables (one for each stock symbol) with 7.3M rows each?
 - any recommendation of database engine? (I&#39;m planning to use Amazon RDS&#39; MySQL)

I&#39;m not used to deal with datasets this big, so this is an excellent opportunity for me to learn. I will appreciate a lot your help and advice.

Edit:

This is a sample row:

&gt; &#39;XX&#39;, 20041208, 938, 43.7444, 43.7541, 43.735, 43.7444, 35116.7, 1, 0, 0

Column 1 is the stock symbol, column 2 is the date, column 3 is the minute, the rest are open-high-low-close prices, volume, and 3 integer columns.

Most of the queries will be like &quot;Give me the prices of AAPL between April 12 2012 12:15 and April 13 2012 12:52&quot;

About the hardware: I plan to use Amazon RDS so I&#39;m flexible on that 

How to store 7.3 billion rows of market data (optimized to be read)?

I am using django 1.2 and going from one view to another using the urlresolvers reverse method.

    url = reverse(viewOne)

and I want to pass a get parameter, for example 

&gt; name = &#39;joe&#39;

so that in the viewOne if I do 

    def viewOne(request):
        request.GET[&#39;name&#39;]
I will get

    joe

how do I do that ? 

How do i pass GET parameters using django urlresolvers reverse

In my Django app, I need to get the host name from the referrer in `request.META.get(&#39;HTTP_REFERER&#39;)` along with its protocol so that from URLs like:

- https://docs.google.com/spreadsheet/ccc?key=blah-blah-blah-blah#gid=1
- https://stackoverflow.com/questions/1234567/blah-blah-blah-blah
- http://www.example.com
- https://www.other-domain.com/whatever/blah/blah/?v1=0&amp;v2=blah+blah ...

I should get:

- https://docs.google.com/
- https://stackoverflow.com/
- http://www.example.com
- https://www.other-domain.com/

I looked over other related questions and found about urlparse, but that didn&#39;t do the trick since

    &gt;&gt;&gt; urlparse(request.META.get(&#39;HTTP_REFERER&#39;)).hostname
    &#39;docs.google.com&#39;


Get protocol + host name from URL

I am following Heroku&#39;s tutorial to deploy a Django app: http://devcenter.heroku.com/articles/django#prerequisites. 

Everything is working fine until I get to this part: 

    $ pip install Django psycopg2

I can install Django by itself, but the probelm is with psycopg2. 

I keep getting this error: 


   

    ld: library not found for -lpq
    
    collect2: ld returned 1 exit status
    
    ld: library not found for -lpq
    
    collect2: ld returned 1 exit status
    
    lipo: can&#39;t open input file: /var/folders/_4/p6l0y0t51hd4xbq7llbyshmw0000gn/T//cc0L10mI.out (No such file or directory)
    
    error: command &#39;gcc-4.2&#39; failed with exit status 1

I&#39;ve installed PostgreSQL 9.1 on my machine. 

Also, in the output, there are bunch of lines like this: 

    gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -isysroot /Developer/SDKs/MacOSX10.6.sdk -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -DPSYCOPG_DEFAULT_PYDATETIME=1 -DPSYCOPG_VERSION=&quot;2.4.4 (dt dec pq3 ext)&quot; -DPG_VERSION_HEX=0x090004 -DPSYCOPG_EXTENSIONS=1 -DPSYCOPG_NEW_BOOLEAN=1 -DHAVE_PQFREEMEM=1 -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -I. -I/usr/include -I/usr/include/postgresql/server -c psycopg/typecast.c -o build/temp.macosx-10.6-intel-2.7/psycopg/typecast.o

I&#39;m not really sure what it means, but I do notice that it has &quot;macosx-10.6&quot; in it so I&#39;m wondering if that could be the issue? I&#39;m on 10.7. 

Thanks in advance for your help. 

Can&#39;t install psycopg2 with pip in virtualenv on Mac OS X 10.7

I am using Play Framework 1.2.4 with `PostgreSQL` and `JPA`. I would like to have a Model hierarchy and see that there are some alternatives to doing this.

I have a base class (which is abstract) and two concrete classes extending this base class. I don&#39;t want to persist this base class while I want to have concrete classes. In the base class, I have another Model classes as properties, in other words, I have `@ManyToOne` relationships in my base class. 

My question is what is the best way of implementing this? Using `@MappedSuperclass` or `@Inheritance` with `TABLE_PER_CLASS` strategy? I am a bit confused as they seem *virtually* equivalent.

I also have some concerns about querying and performance issues that I might face in future.

JPA: Implementing Model Hierarchy - @MappedSuperclass vs. @Inheritance

I understand that JPA 2 is a specification and Hibernate is a tool for ORM. Also, I understand that Hibernate has more features than JPA 2. But from a practical point of view, what really is the difference? 

I have experience using iBatis and now I&#39;m trying to learn either Hibernate or JPA2. I picked up Pro JPA2 book and it keeps referring to &quot;JPA provider&quot;. For example:

&gt;  If you think a feature should be standardized, you should speak up
&gt; and request it from your JPA provider

This confuses me so I have a few questions:

- Using JPA2 alone can I fetch data from DB by simply annotating my POJO&#39;s
- Is JPA2 supposed to be used with a &quot;JPA Provider&quot; e.g TopLink or Hibernate? If so, then what&#39;s the benefit of using JPA2 + Hibernate as compared to JPA2 alone, or compared to Hibernate alone ?
- Can you recommend a good practical JPA2 book. &quot;Pro JPA2&quot; seems more like a bible and reference on JPA2 (It doesn&#39;t get into Queries until the later half of the book). Is there a book that takes a problem/solution approach to JPA2?

What&#39;s the difference between JPA and Hibernate?

I&#39;m writing a quick and dirty maintenace script to delete some rows and would like to avoid having to bring my ORM classes/mappings over from the main project.  I have a query that looks similar to:

    address_table = Table(&#39;address&#39;,metadata,autoload=True)
    addresses = session.query(addresses_table).filter(addresses_table.c.retired == 1)

According to everything I&#39;ve read, if I was using the ORM (not &#39;just&#39; tables) and passed in something like:

    addresses = session.query(Addresses).filter(addresses_table.c.retired == 1)

I could add a `.delete()` to the query, but when I try to do this using only tables I get a complaint:

    File &quot;/usr/local/lib/python2.6/dist-packages/sqlalchemy/orm/query.py&quot;, line 2146, in delete
        target_cls = self._mapper_zero().class_
    AttributeError: &#39;NoneType&#39; object has no attribute &#39;class_&#39;

Which makes sense as its a table, not a class.  I&#39;m quite green when it comes to SQLAlchemy, how should I be going about this?

How to delete rows from a table using an SQLAlchemy query without ORM?

Can someone please explain the difference between **Dapper.Rainbow** vs. **Dapper.Contrib**?

I mean when do you use SqlMapperExtensions.cs of Dapper.Contrib and when should you use Dapper.Rainbow?

Dapper.Rainbow VS Dapper.Contrib

In JPA there is an attribute called `referencedColumnName` that can be set on `@JoinColumn, @PrimaryKeyJoinColumn` what is the idea behind this setting, can someone give a good example of where this can be used?

What is referencedColumnName used for in JPA?

I have the following 2 models

    class Sport &lt; ActiveRecord::Base
      has_many :charts, order: &quot;sortWeight ASC&quot;
      has_one :product, :as =&gt; :productable
      accepts_nested_attributes_for :product, :allow_destroy =&gt; true
    end

    class Product &lt; ActiveRecord::Base
      belongs_to :category
      belongs_to :productable, :polymorphic =&gt; true
    end

A sport can&#39;t exist without the product, so in my `sports_controller.rb` I had:

    def new
      @sport = Sport.new
      @sport.product = Product.new
    ...
    end

I tried to move the creation of the product to the sport model, using `after_initialize`:

    after_initialize :create_product

    def create_product
     self.product = Product.new
    end

I quickly learned that `after_initialize` is called whenever a model is instantiated (i.e., from a `find` call).  So that wasn&#39;t the behavior I was looking for.

Whats the way I should be modeling the requirement that all `sport` have a `product`?

Thanks





Rails after_initialize only on &quot;new&quot;

I need to check if `Model.objects.filter(...)` turned up anything, but do not need to insert anything. My code so far is:

    user_pass = log_in(request.POST)  # form class
    if user_pass.is_valid():
        cleaned_info = user_pass.cleaned_data
        user_object = User.objects.filter(email = cleaned_info[&#39;username&#39;])




Check if an object exists

I started a Rails app and everything works fine. But now, I would like to rename a controller and the associated model:

I wanted to change the `Corps` controller to `Stores` and the same (without final s) for the model.

Looking on google, people suggested to destroy and then generate again the controller and model. The problem is that it will erase the actual code of each files!

Any solution? Thanks in advance.

How to rename rails controller and model in a project

I have what I think is probably a very obvious question, but I couldn&#39;t find an answer anywhere.

I am just trying to load some JSON data from my server into the client. Right now, I am using JQuery to load it with an AJAX call (code below).

    &lt;script type=&quot;text/javascript&quot;&gt;
    var global = new Array();
    $.ajax({
        url: &quot;/json&quot;,
        success: function(reports){
            global = reports;
            return global;
            }
        });
    &lt;/script&gt;

This is located in the html file. It works so far, but the issue is that I want to use AngularJS. Now, while Angular CAN use the variables, i cannot load the whole thing into a variable so I can use a for each loop. This seems to be related to the &quot;$Scope&quot;, which is usually located in the .js file.

The problem is that I cannot load code from other pages into a .js file. Every example of Angular only shows stuff like this:

    function TodoCtrl($scope) {
      $scope.todos = [
        {text:&#39;learn angular&#39;, done:true},
        {text:&#39;build an angular app&#39;, done:false}];

So, this is useful, if I 
A) Want to type all of this by hand, AND 
B) If I know in advance what all my data is...

I don&#39;t know in advance (the data is dynamic) and I don&#39;t want to type it. 

So, when I tried to change the AJAX call to Angular using $Resource, it doesn&#39;t seem to work. Maybe I can&#39;t figure it out, but it is a relatively simple GET request for JSON data.

**tl:dr I can&#39;t get AJAX calls to work in order to load external data into an angular model.**

How to load json into my angular.js ng-model?

I am trying to learn domain-driven design (DDD), and I think I got the basic idea. But there is something confusing me.

In DDD, are the persistence model and domain model different things? I mean, we design our domain and classes with only domain concerns in mind; that&#39;s okay. But after that when we are building our repositories or any other data persistence system, should we create another representation of our model to use in persistence layer?

I was thinking our domain model is used in persistence too, meaning our repositories return our domain objects from queries. But today, I read this post, and I&#39;m a little confused:

*[Just Stop It! The Domain Model Is Not The Persistence Model][1]*

If that&#39;s true what would be the advantage of having separate persistence objects from domain objects?

  [1]: https://blog.sapiensworks.com/post/2012/04/07/Just-Stop-It!-The-Domain-Model-Is-Not-The-Persistence-Model.aspx


Content Type	Original Author	Original Content on Stackoverflow
Question	Goro	View Question on Stackoverflow
Solution 1 - Python	Abid A	View Answer on Stackoverflow
Solution 2 - Python	niko.makela	View Answer on Stackoverflow
Solution 3 - Python	jsh	View Answer on Stackoverflow

How can I iterate over ManyToManyField?

Python Problem Overview

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Removing badge from iOS app icon

Show row number in row header of a DataGridView

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