Just use the current directory:

`cd /home/user/projectfolder`

`django-admin.py startproject project .`

The use of `.` just instructs Django to create a project in the current directory while:

`django-admin.py startproject`

instructs Django to create a project and create the necessary directory

&gt; If only the project name is given, both the project directory and
&gt; project package will be named &lt;projectname&gt; and the project directory
&gt; will be created in the current working directory.

This fails because of the existing directory **which is not a bug** but a constrain in order to prevent accidents.

You can make too like this:
&lt;pre&gt; django-admin startproject name_project path_project &lt;/pre&gt;
Example:
&lt;pre&gt; django-admin startproject example /tmp/example &lt;/pre&gt;


What is the best way to handle expired tokens in laravel 5. 

I mean I have a page and it has some links which perform ajax requests. They work fine when the page is loaded but when I wait for sometime then I get a TOKEN MISMATCH error. 

Now, I have to refresh the page to make it work again. BUT, I don&#39;t want to refresh the page. I want some way to refresh the token or some other work around to make it fix.

I hope you got my point.

Handling expired token in Laravel

I am creating an Azure AD app and noticed there are two permissions types, Application Permissions and Delegated Permissions.  What is the difference between the two and under what scenario should I use them?

Azure AD App Application Permissions vs Delegated Permissions

I want to start new django project in already existing folder and obviously get 

    CommandError: &#39;/home/user/projectfolder&#39; already exists.

Is there some way to force startproject command to create project in an existing folder? I have some important data in that folder and also git folder so I don&#39;t want to move it somewhere and then move it back.

Force django-admin startproject if project folder already exists

I want to start new django project in already existing folder and obviously get
<pre><code class="hljs language-arduino">CommandError: '/home/user/projectfolder' already exists.
</code></pre>
Is there some way to force startproject command to create project in an existing folder? I have some important data in that folder and also git folder so I don't want to move it somewhere and then move it back.

How can I find median of an `RDD` of integers using a distributed method, IPython, and Spark? The `RDD` is approximately 700,000 elements and therefore too large to collect and find the median.

This question is similar to this question. However, the answer to the question is using Scala, which I do not know.

https://stackoverflow.com/questions/28158729/how-can-i-calculate-exact-median-with-apache-spark

Using the thinking for the Scala answer, I am trying to write a similar answer in Python.

I know I first want to sort the `RDD`. I do not know how. I see the `sortBy` (Sorts this RDD by the given `keyfunc`) and `sortByKey` (Sorts this `RDD`, which is assumed to consist of (key, value) pairs.) methods. I think both use key value and my `RDD` only has integer elements.

1. First, I was thinking of doing `myrdd.sortBy(lambda x: x)`? 
2. Next I will find the length of the rdd (`rdd.count()`).
3. Finally, I want to find the element or 2 elements at the center of the rdd. I need help with this method too.

EDIT:

I had an idea. Maybe I can index my `RDD` and then key = index and value = element. And then I can try to sort by value? I don&#39;t know if this is possible because there is only a `sortByKey` method.

How to find median and quantiles using Spark

I want to make a function that returns a copy of a dictionary excluding keys specified in a list.

Considering this dictionary:

    my_dict = {
        &quot;keyA&quot;: 1,
        &quot;keyB&quot;: 2,
        &quot;keyC&quot;: 3
    }

A call to `without_keys(my_dict, [&#39;keyB&#39;, &#39;keyC&#39;])` should return:

    {
        &quot;keyA&quot;: 1
    }

I would like to do this in a one-line with a neat dictionary comprehension but I&#39;m having trouble. My attempt is this:

	def without_keys(d, keys):
		return {k: d[f] if k not in keys for f in d}

which is invalid syntax. How can I do this?

Return copy of dictionary excluding specified keys

**app.py**

    from flask import Flask, render_template, request,jsonify,json,g
    import mysql.connector
    
    app = Flask(__name__)
    **class TestMySQL():**
      @app.before_request
      def before_request():
        try:
           g.db = mysql.connector.connect(user=&#39;root&#39;, password=&#39;root&#39;, database=&#39;mysql&#39;)
        except mysql.connector.errors.Error as err:
          resp = jsonify({&#39;status&#39;: 500, &#39;error&#39;: &quot;Error:{}&quot;.format(err)})
          resp.status_code = 500
          return resp
    @app.route(&#39;/&#39;)
    def input_info(self):
        try:     
            cursor = g.db.cursor()
            cursor.execute (&#39;CREATE TABLE IF NOT EXISTS testmysql (id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, name VARCHAR(40) NOT NULL, \
                     email VARCHAR(40) NOT NULL UNIQUE)&#39;)
            cursor.close()


test.py

    from app import *
    class Test(unittest.TestCase):         
     def test_connection1(self):  
       with patch(&#39;__main__.mysql.connector.connect&#39;) as  mock_mysql_connector_connect:
       object=TestMySQL()
       object.before_request()  &quot;&quot;&quot;Runtime error on calling this&quot;  
       
     
     
I am importing **app** into **test.py** for unit testing.On calling  &#39;*before_request*&#39; function into test.py ,it is throwing RuntimeError: working outside of application context
same is happening on calling &#39;*input_info()*&#39;


RuntimeError: working outside of application context

There is a `-&gt;`, or dash-greater-than symbol at the end of a python method, and I&#39;m not sure what it means. One might call it an arrow as well.

Here is the example:


    @property
    def get_foo(self) -&gt; Foo:
        return self._foo

where `self._foo` is an instance of Foo. 

My guess is that it is some kind of static type declaration, to tell the interpreter that `self._foo` is of type Foo. But when I tested this, if `self._foo` is not an instance of Foo, nothing unusual happens. Also, if `self._foo` is of a type other than Foo, let&#39;s say it was an `int`, then `type(SomeClass.get_foo())` returns `int`. So, what&#39;s the point of `-&gt; Foo`?

This concept is hard to lookup because it is a symbol without a common name, and the term &quot;arrow&quot; is misleading.


What does the -&gt; (dash-greater-than arrow symbol) mean in a Python method signature?

Why does Python 3 allow &quot;00&quot; as a literal for 0 but not allow &quot;01&quot; as a literal for 1? Is there a good reason? This inconsistency baffles me. (And we&#39;re talking about Python 3, which purposely broke backward compatibility in order to achieve goals like consistency.)

For example:

    &gt;&gt;&gt; from datetime import time
    &gt;&gt;&gt; time(16, 00)
    datetime.time(16, 0)
    &gt;&gt;&gt; time(16, 01)
      File &quot;&lt;stdin&gt;&quot;, line 1
        time(16, 01)
                  ^
    SyntaxError: invalid token
    &gt;&gt;&gt;

Why does Python 3 allow &quot;00&quot; as a literal for 0 but not allow &quot;01&quot; as a literal for 1?

I have a project that spans multiple apps:

    ./project/app1
    ./project/app2
    ./project/...

Each app has a router for Django REST Framework to incorporate the parts of the API provided by that app:

    from django.conf.urls import url, include
    from rest_framework.routers import DefaultRouter
    from .views import ThingViewSet
    
    router = DefaultRouter()
    router.register(r&#39;things&#39;, ThingViewSet, base_name=&#39;thing&#39;)
    
    urlpatterns = [
        url(r&#39;^&#39;, include(router.urls)),
    ]

Because the apps are separate, my top-level URLs file (`./project/urls.py`) includes each of the URLs files from the separate apps:

    url(r&#39;^api/app1/&#39;, include(&#39;app1.urls&#39;, namespace=&#39;a1&#39;)),
    url(r&#39;^api/app2/&#39;, include(&#39;app2.urls&#39;, namespace=&#39;a2&#39;)),

This means that Django REST Framework shows a separate API root for each app. What I would like, however, is a unified API structure, so that if I navigate to `http://example.com/api/` I see the full list of all URLs that are available at that level of the hierarchy.

I presume there is a way to include all my separate routers defined in the individual `urls.py` files for each app into a single router, but I can&#39;t find documentation on how to do this. Am I missing something obvious?

Django REST Framework combining routers from different apps

I am building a real world application where users will access the app primarily from Android, iOS devices as well as Desktops.

From my elementary research, I have realized that token based authentication mechanism is more better and elegant for client-server models as compared to session based authentication.

In Django, I have found two popular ways to do this -

1. [http://www.django-rest-framework.org/api-guide/authentication/#tokenauthentication][1]
2. [http://getblimp.github.io/django-rest-framework-jwt/][2]

From what I understood, option 2] is an extension of 1] except that the Token is in the form of JSON(serialized). I would like to understand what other differences there are between option 1] and 2] and the advantages/disadvantages of choosing either.


  [1]: http://www.django-rest-framework.org/api-guide/authentication/#tokenauthentication
  [2]: http://getblimp.github.io/django-rest-framework-jwt/

Django : DRF Token based Authentication VS JSON Web Token

I have a ViewSet like this one to list users&#39; data:

    class Foo(viewsets.ViewSet):
    
        def list(self, request):
            queryset = User.objects.all()
            serializer = UserSerializer(queryset, many=True)
            return Response(serializer.data)
    
I want to turn on pagination like the default pagination for ModelViewSet:

    {
        &quot;count&quot;: 55,
        &quot;next&quot;: &quot;http://myUrl/?page=2&quot;,
        &quot;previous&quot;: null,
        &quot;results&quot;: [{...},{...},...,{...}]
    }
    
[The official doc][1] says: 

&gt; Pagination is only performed automatically if you&#39;re using the generic views or viewsets

...but my resultset is not paginated at all. How can I paginate it?


  [1]: http://www.django-rest-framework.org/api-guide/pagination/

Django Rest Framework: turn on pagination on a ViewSet (like ModelViewSet pagination)

In Django, is there an easy way to check whether all database migrations have been run? I&#39;ve found `manage.py migrate --list`, which gives me the information I want, but the format isn&#39;t very machine readable.

For context: I have a script that shouldn&#39;t start running until the database has been migrated. For various reasons, it would be tricky to send a signal from the process that&#39;s running the migrations. So I&#39;d like to have my script periodically check the database to see if all the migrations have run.

Check for pending Django migrations

I am trying to figure out the best way to add annotated fields, such as any aggregated (calculated) fields to DRF (Model)Serializers. My use case is simply a situation where an endpoint returns fields that are NOT stored in a database but calculated from a database.

Let&#39;s look at the following example:

models.py

    class IceCreamCompany(models.Model):
        name = models.CharField(primary_key = True, max_length = 255)
        
    class IceCreamTruck(models.Model):
        company = models.ForeignKey(&#39;IceCreamCompany&#39;, related_name=&#39;trucks&#39;)
        capacity = models.IntegerField()

serializers.py

    class IceCreamCompanySerializer(serializers.ModelSerializer):
        class Meta:
            model = IceCreamCompany

desired JSON output:

    [

        {
            &quot;name&quot;: &quot;Pete&#39;s Ice Cream&quot;,
            &quot;total_trucks&quot;: 20,
            &quot;total_capacity&quot;: 4000
        },
        ...
    ]

I have a couple solutions that work, but each have some issues.

**Option 1: add getters to model and use SerializerMethodFields**

models.py

    class IceCreamCompany(models.Model):
        name = models.CharField(primary_key=True, max_length=255)

        def get_total_trucks(self):
            return self.trucks.count()
        
        def get_total_capacity(self):
            return self.trucks.aggregate(Sum(&#39;capacity&#39;))[&#39;capacity__sum&#39;]


serializers.py

    class IceCreamCompanySerializer(serializers.ModelSerializer):

        def get_total_trucks(self, obj):
            return obj.get_total_trucks

        def get_total_capacity(self, obj):
            return obj.get_total_capacity

        total_trucks = SerializerMethodField()
        total_capacity = SerializerMethodField()
        
        class Meta:
            model = IceCreamCompany
            fields = (&#39;name&#39;, &#39;total_trucks&#39;, &#39;total_capacity&#39;)

The above code can perhaps be refactored a bit, but it won&#39;t change the fact that this option will perform 2 extra SQL queries *per IceCreamCompany* which is not very efficient.

**Option 2: annotate in ViewSet.get_queryset**

models.py as originally described.

views.py

    class IceCreamCompanyViewSet(viewsets.ModelViewSet):
        queryset = IceCreamCompany.objects.all()
        serializer_class = IceCreamCompanySerializer

        def get_queryset(self):
            return IceCreamCompany.objects.annotate(
                total_trucks = Count(&#39;trucks&#39;),
                total_capacity = Sum(&#39;trucks__capacity&#39;)
            )

This will get the aggregated fields in a single SQL query but I&#39;m not sure how I would add them to the Serializer as DRF doesn&#39;t magically know that I&#39;ve annotated these fields in the QuerySet. If I add total_trucks and total_capacity to the serializer, it will throw an error about these fields not being present on the Model. 

Option 2 can be made work without a serializer by using a [View](http://www.django-rest-framework.org/api-guide/views/) but if the model contains a lot of fields, and only some are required to be in the JSON, it would be a somewhat ugly hack to build the endpoint without a serializer.

Aggregate (and other annotated) fields in Django Rest Framework serializers

Trying to create a super user for my database:

    manage.py createsuperuser

Getting a sad recursive message:

*Superuser creation skipped due to not running in a TTY. You can run `manage.py createsuperuser` in your project to create one manually.*

Seriously Django? Seriously?


The only information I found for this was the one listed above but it didn&#39;t work:
https://stackoverflow.com/questions/26980003/unable-to-create-superuser-in-django-due-to-not-working-in-tty

And this other one here, which is basically the same:
https://stackoverflow.com/questions/14059573/cant-create-super-user-django



Not able to create super user with Django manage.py

How to check in template whether user belongs to some group? 

It is possible in a `view` which is generating the `template` but what if I want to check this in `base.html` which is an extending template (it does not have it&#39;s own view function)?

All of my templates extends `base.html` so it is not good to check it in each `view`. 

The `base.html` contains upper bar, which should contain buttons depending on in which `group` logged user is (Customers, Sellers).  

In my `base.html` is:

    {% if user.is_authenticated %}

which is not enough because I have to act differently to users from `Customers` and users from `Sellers`.

So the thing I want is:

    {% if user.in_group(&#39;Customers&#39;) %}
     &lt;p&gt;Customer&lt;/p&gt;
    {% endif %}
    {% if user.in_group(&#39;Sellers&#39;) %}
    &lt;p&gt;Seller&lt;/p&gt;
    {% endif %}

Content Type	Original Author	Original Content on Stackoverflow
Question	valignatev	View Question on Stackoverflow
Solution 1 - Python	petkostas	View Answer on Stackoverflow
Solution 2 - Python	Elinaldo Monteiro	View Answer on Stackoverflow

Force django-admin startproject if project folder already exists

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

Azure AD App Application Permissions vs Delegated Permissions

Handling expired token in Laravel

Attributions