There is a difference between the two: 

In the case of `HttpResponseRedirect` the first argument can only be a `url`. 

`redirect` which will _ultimately_ return a `HttpResponseRedirect` can accept a `model`, `view`, or `url` as it&#39;s &quot;to&quot; argument. So it is a little more flexible in what it can &quot;redirect&quot; to. 

I also like how `redirect` is shorter. So I&#39;d use `redirect` over `HttpResponseRedirect`. 

Both are fine to use though.

From documentation - 

&gt; `redirect(to[, permanent=False], *args, **kwargs)` Returns an
&gt; `HttpResponseRedirect` to the appropriate URL for the arguments passed.

from the definition its the same. Thats what shortcuts are for. Both are one and the same.

shortcuts generally are written one level above the actual API&#39;s. So `redirect` encapsulates `HttpResponseRedirect` and `HttpResponsePermanentRedirect` with the arg `permanent=False`. 

There is no major downside to using `HttpResponseRedirect` over `redirect`. Hope this clears it.

Under Linux, I&#39;ve been checking out matplotlib&#39;s animation class, and it seems to work except that I cant initialise the movie writer to write out the movie.

Using either of the examples:

 * &lt;http://matplotlib.org/examples/animation/moviewriter.html&gt;
 * &lt;http://matplotlib.org/examples/animation/basic_example_writer.html&gt;

results in the error &quot;**RuntimeError: No MovieWriters available!**&quot;

Im using matplotlib version 1.3.x and have installed (hopefully) all the codecs.

Can someone please suggest as to why I get this error? If its a codecs issue, which codecs (+versions) should I install?
If its something else that&#39;s broken, is there an alternative for creating animations in python?

Matplotlib-Animation &quot;No MovieWriters Available&quot;

I faced this problem many times during various situations. It is generic to all programming languages although I am comfortable with C or Java.

Let us consider two arrays (or collections):

    char[] A = {&#39;a&#39;, &#39;b&#39;, &#39;c&#39;, &#39;d&#39;};
    char[] B = {&#39;c&#39;, &#39;d&#39;, &#39;e&#39;, &#39;f&#39;};

How do I get the common elements between the two arrays as a new array?
In this case, the intersection of array A and B is `char[] c = {&#39;c&#39;, &#39;d&#39;}`.

I want to avoid the repeated iteration of one array inside the other array which will
increase the execution time by (length of A times length of B) which is too much in the case of huge arrays.

Is there any way we could do a single pass in each array to get the common elements?


How do I get the intersection between two arrays as a new array?

Which is it better to use generally?

 - https://docs.djangoproject.com/en/dev/topics/http/shortcuts/#redirect

 - https://docs.djangoproject.com/en/dev/ref/request-response/#django.http.HttpResponseRedirect

Is there any advantage to writing:

    return redirect(my_url)

over:

    return HttpResponseRedirect(my_url)

Or is it a direct alias? Is there any difference? Which is more pythonic/django-nic?

What the difference between using Django redirect and HttpResponseRedirect?

Which is it better to use generally?
<ul>
<li>
<a href="https://docs.djangoproject.com/en/dev/topics/http/shortcuts/#redirect" target="_blank" rel="noopener noreferrer">https://docs.djangoproject.com/en/dev/topics/http/shortcuts/#redirect</a>
</li>
<li>
<a href="https://docs.djangoproject.com/en/dev/ref/request-response/#django.http.HttpResponseRedirect" target="_blank" rel="noopener noreferrer">https://docs.djangoproject.com/en/dev/ref/request-response/#django.http.HttpResponseRedirect</a>
</li>
</ul>
Is there any advantage to writing:
<pre><code class="hljs language-kotlin">return redirect(my_url)
</code></pre>
over:
<pre><code class="hljs language-kotlin">return HttpResponseRedirect(my_url)
</code></pre>
Or is it a direct alias? Is there any difference? Which is more pythonic/django-nic?

I have a matplotlib plot with a colorbar attached. I want to position the colorbar so that it is horizontal, and underneath my plot.

I have almost done this via the following:

    plt.colorbar(orientation=&quot;horizontal&quot;,fraction=0.07,anchor=(1.0,0.0))

But the colorbar is still overlapping with the plot slightly (and the labels of the x axis). I want to move the colorbar further down, but I can&#39;t figure out how to do it.

Positioning the colorbar

I have a complex Flask-based web app.  There are lots of separate files with view functions.  Their URLs are defined with the `@app.route(&#39;/...&#39;)` decorator.  Is there a way to get a list of all the routes that have been declared throughout my app?  Perhaps there is some method I can call on the `app` object?

Get list of all routes defined in the Flask app

I have one list of 100 numbers as height for Y axis, and as length for X axis: 1 to 100  with a constant step of 5. I need to calculate the Area that it is included by the curve of the (x,y) points, and the X axis, using rectangles and Scipy. Do I have to find the function of this curve? or not? ... almost all the examples I have read are about a specific equation for the Y axis. In my case there is no equation, just data from a list. The classic solution is to add or the Y points and multiple by the step X distance... using Scipy any idea?

Please, can anyone recommend any book which focusing on numerical (finite elementary) methods, using Scipy and Numpy? ...


Calculating the area under a curve given a set of coordinates, without knowing the function

How Do I add a single item to a serialized panda series. I know it&#39;s not the most efficient way memory wise, but i still need to do that.

Something along:

    &gt;&gt; x = Series()
    &gt;&gt; N = 4
    &gt;&gt; for i in xrange(N):
    &gt;&gt;     x.some_appending_function(i**2)    
    &gt;&gt; print x
    
    0 | 0
    1 | 1
    2 | 4
    3 | 9

also, how can i add a single row to a pandas DataFrame? 

How to add a single item to a Pandas Series

Let&#39;s pretend I have the following QueryDict: 

    &lt;QueryDict: {u&#39;num&#39;: [0], u&#39;var1&#39;: [u&#39;value1&#39;, u&#39;value2&#39;], u&#39;var2&#39;: [u&#39;8&#39;]}&gt;

I&#39;d like to have a dictionary out of this, eg:

    {&#39;num&#39;: [0], &#39;var1&#39;:[&#39;value1&#39;, &#39;value2&#39;], &#39;var2&#39;:[&#39;8&#39;]}

(I don&#39;t care if the unicode symbol `u` stays or goes.)

If I do `queryDict.dict()`, as suggested by the [django site][1], I lose the extra values belonging to `var1`, eg:

    {&#39;num&#39;: [0], &#39;var1&#39;:[&#39;value2&#39;], &#39;var2&#39;:[&#39;8&#39;]}

I was thinking of doing this:

    myDict = {}
    for key in queryDict.iterkeys():
        myDict[key] = queryDict.getlist(key)

Is there a better way? 


  [1]: https://docs.djangoproject.com/en/dev/ref/request-response/#django.http.QueryDict.dict

How to change a django QueryDict to Python Dict?

I&#39;m trying to get Celery logging working with `Django`. I have logging set-up in `settings.py` to go to console (that works fine as I&#39;m hosting on `Heroku`). At the top of each module, I have:

    import logging
    logger = logging.getLogger(__name__)

And in my tasks.py, I have:

    from celery.utils.log import get_task_logger
    logger = get_task_logger(__name__)

That works fine for logging calls from a task and I get output like this:

    2012-11-13T18:05:38+00:00 app[worker.1]: [2012-11-13 18:05:38,527: INFO/PoolWorker-2] Syc feed is starting

But if that task then calls a method in another module, e.g. a `queryset` method, I get duplicate log entries, e.g.

    2012-11-13T18:00:51+00:00 app[worker.1]: [INFO] utils.generic_importers.ftp_processor process(): File xxx.csv already imported. Not downloaded
    2012-11-13T18:00:51+00:00 app[worker.1]: [2012-11-13 18:00:51,736: INFO/PoolWorker-6] File xxx.csv already imported. Not downloaded

I think I could use

    CELERY_HIJACK_ROOT_LOGGER = False
to just use the `Django` logging but this didn&#39;t work when I tried it and even if I did get it to work, I would lose the `&quot;PoolWorker-6&quot;` bit which I do want. (Incidentally, I can&#39;t figure out how to get the task name to display in the log entry from Celery, as [the docs][docs] seems to indicate that it should).

I suspect I&#39;m missing something simple here.

[docs]: http://docs.celeryproject.org/en/master/configuration.html?highlight=celeryd_task_log_format#std:setting-CELERYD_TASK_LOG_FORMAT

Django Celery Logging Best Practice

I have model that looks like this:

    class Category(models.Model):
        parentCategory = models.ForeignKey(&#39;self&#39;, blank=True, null=True, related_name=&#39;subcategories&#39;)
        name = models.CharField(max_length=200)
        description = models.CharField(max_length=500)

I managed to get flat json representation of all categories with serializer:

    class CategorySerializer(serializers.HyperlinkedModelSerializer):
        parentCategory = serializers.PrimaryKeyRelatedField()
        subcategories = serializers.ManyRelatedField()

        class Meta:
            model = Category
            fields = (&#39;parentCategory&#39;, &#39;name&#39;, &#39;description&#39;, &#39;subcategories&#39;)

Now what I want to do is for subcategories list to have inline json representation of subcategories instead of their ids. How would I do that with django-rest-framework? I tried to find it in documentation, but it seems incomplete.



Django rest framework nested self-referential objects

I have a fairly simple query I&#39;d like to make via the ORM, but can&#39;t figure that out..

I have three models:

Location (a place), Attribute (an attribute a place might have), and Rating (a M2M &#39;through&#39; model that also contains a score field)

I want to pick some important attributes and be able to rank my locations by those attributes - i.e. higher total score over all selected attributes = better.

I can use the following SQL to get what I want:

    select location_id, sum(score) 
        from locations_rating 
        where attribute_id in (1,2,3) 
        group by location_id order by sum desc;

which returns

     location_id | sum 
    -------------+-----
              21 |  12
               3 |  11

The closest I can get with the ORM is:

    Rating.objects.filter(
        attribute__in=attributes).annotate(
        acount=Count(&#39;location&#39;)).aggregate(Sum(&#39;score&#39;))

Which returns 

    {&#39;score__sum&#39;: 23}

i.e. the sum of all, not grouped by location.

Any way around this? I could execute the SQL manually, but would rather go via the ORM to keep things consistent.

Thanks

How to group by AND aggregate with Django

I have a Postgres schema which looks like:

![enter image description here][1]

The problem is that whenever I save text longer than 500 characters in the description column I get the error:

    value too long for type character varying(500)

In the documentation for Postgres it says type text can have unlimited characters.

I&#39;m using postgresql-9.1.

This table has been generated using Django 1.4 and the field type in the model is TextField, if that helps explain the problem further.

Any ideas as why this is happening and what I can do to fix it?

  [1]: http://i.stack.imgur.com/wQ4l0.png

Strange PostgreSQL &quot;value too long for type character varying(500)&quot;

I&#39;m trying to establish a login mechanism using node.js, express and passport.js. The Login itself works quite nice, also sessions are stored nicely with redis but I do have some troubles with redirecting the user to where he started from before being prompted to authenticate.

e.g. User follows link `http://localhost:3000/hidden` is then redirected to `http://localhost:3000/login` but then I want him to be redirected again back to `http://localhost:3000/hidden`.

The purpose of this is, if the user access randomly a page he needs to be logged in first, he shall be redirected to the /login site providing his credentials and then being redirected back to the site he previously tried to access.

Here is my login post

    app.post(&#39;/login&#39;, function (req, res, next) {
        passport.authenticate(&#39;local&#39;, function (err, user, info) {
            if (err) {
                return next(err)
            } else if (!user) { 
                console.log(&#39;message: &#39; + info.message);
                return res.redirect(&#39;/login&#39;) 
            } else {
                req.logIn(user, function (err) {
                    if (err) {
                        return next(err);
                    }
                    return next(); // &lt;-? Is this line right?
                });
            }
        })(req, res, next);
    });

and here my ensureAuthenticated Method

    function ensureAuthenticated (req, res, next) {
      if (req.isAuthenticated()) { 
    	  return next();
      }
      res.redirect(&#39;/login&#39;);
    }

which hooks into the `/hidden` page

    app.get(&#39;/hidden&#39;, ensureAuthenticated, function(req, res){
        res.render(&#39;hidden&#39;, { title: &#39;hidden page&#39; });
    });

The html output for the login site is quite simple

&lt;!-- language: lang-html --&gt;

    &lt;form method=&quot;post&quot; action=&quot;/login&quot;&gt;
      
      &lt;div id=&quot;username&quot;&gt;
        &lt;label&gt;Username:&lt;/label&gt;
        &lt;input type=&quot;text&quot; value=&quot;bob&quot; name=&quot;username&quot;&gt;
      &lt;/div&gt;
      
      &lt;div id=&quot;password&quot;&gt;
        &lt;label&gt;Password:&lt;/label&gt;
        &lt;input type=&quot;password&quot; value=&quot;secret&quot; name=&quot;password&quot;&gt;
      &lt;/div&gt;
    
      &lt;div id=&quot;info&quot;&gt;&lt;/div&gt;
        &lt;div id=&quot;submit&quot;&gt;
        &lt;input type=&quot;submit&quot; value=&quot;submit&quot;&gt;
      &lt;/div&gt;
    
    &lt;/form&gt;

Redirecting to previous page after authentication in node.js using passport.js

I am trying to throw command output to file plus console also. This is because i want to keep record of output in file. I am doing following and it appending to file but not printing `ls` output on terminal. 

    $ls 2&gt;&amp;1 &gt; /tmp/ls.txt

Command output redirect to file and terminal

I have the following htaccess code:

    &lt;IfModule mod_rewrite.c&gt;
    
    RewriteEngine On
    RewriteCond !{HTTPS} off
    RewriteRule ^(.*)$ https://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
    RewriteCond %{HTTP_HOST} !^www\.
    RewriteRule ^(.*)$ https://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
    
    &lt;/IfModule&gt;

I want my site to be redirected to `https://www.` with HTTPS, and enforcing the `www.` subdomain,
but when I access `http://www.` (without HTTPS), it does not redirect me to `https://www` with HTTPS.


htaccess redirect to https://www

I know it&#39;s possible to link directly to an app in iOS by registering a custom scheme (e.g. so://) and it&#39;s also possible to link to the app in the appstore via itunes.

In many cases, the ideal flow is to provide a link that redirects to the app _if_ it&#39;s installed and to the store if not. Is this possible, and if so, how?

**Added for clarity**, the scenario is I&#39;m opening a link (http) from an e-mail on my iphone that&#39;s inviting me to join a group in an application. If the user has the app installed on that device it should open, otherwise the http link should redirect to itunes.

Redirect to application if installed, otherwise to App Store

I&#39;m new to Python and Flask and I&#39;m trying to do the equivalent of `Response.redirect` as in C# - ie: redirect to a specific URL - how do I go about this?

Here is my code:

    import os
    from flask import Flask
    
    app = Flask(__name__)
    
    @app.route(&#39;/&#39;)
    def hello():
        return &#39;Hello World!&#39;
    
    if __name__ == &#39;__main__&#39;:
        # Bind to PORT if defined, otherwise default to 5000.
        port = int(os.environ.get(&#39;PORT&#39;, 5000))
        app.run(host=&#39;0.0.0.0&#39;, port=port)



Content Type	Original Author	Original Content on Stackoverflow
Question	Williams	View Question on Stackoverflow
Solution 1 - Python	Marwan Alsabbagh	View Answer on Stackoverflow
Solution 2 - Python	Srikar Appalaraju	View Answer on Stackoverflow

What the difference between using Django redirect and HttpResponseRedirect?

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

How do I get the intersection between two arrays as a new array?

Matplotlib-Animation "No MovieWriters Available"

Attributions