    import settings

Will import settings(.py) module of your Django project (if you are writing this code from the &quot;root&quot; package of your application, of course)

    from django.conf import settings

Will import settings **object** from django.conf package (Django&#39;s provided files). [This is important][1], because

&gt; [..] note that your code should not import from either global_settings or your own settings file. django.conf.settings abstracts the concepts of default settings and site-specific settings; it presents a single interface. It also decouples the code that uses settings from the location of your settings.

UPDATE: if you want to define some own settings, see [this part of the documentation][2]



  [1]: https://docs.djangoproject.com/en/dev/topics/settings/#using-settings-in-python-code
  [2]: https://docs.djangoproject.com/en/dev/topics/settings/#custom-default-settings

I am trying to detect if a block of memory was not freed. Of course, the manager tells me that by dialog box or log file, but what if I would like to store results in a database? For example I would like to have in a database table a names of routines which allocated given blocks.

After reading a documentation of FastMM I know that since version 4.98 we have a possibility to be notified by manager about memory allocations, frees and reallocations as they occur. For example `OnDebugFreeMemFinish` event is passing to us a `PFullDebugBlockHeader` which contains useful informations.
There is one thing that `PFullDebugBlockHeader` is missing - the information if the given block was freed by the application.

**Unless `OnDebugFreeMemFinish` is called only for not freed blocks? This is which I do not know and would like to find out.**

The problem is that even hooking into `OnDebugFreeMemFinish` event I was unable to find out if the block was freed or not.

Here is an example:

    program MemLeakTest;
    
    {$APPTYPE CONSOLE}
    
    uses
      FastMM4, ExceptionLog, SysUtils;
    
    
    procedure MemFreeEvent(APHeaderFreedBlock: PFullDebugBlockHeader; AResult: Integer);
    begin
    //This is executed at the end, but how should I know that this block should be freed
    //by application? Unless this is executed ONLY for not freed blocks.
    end;
    
    procedure Leak;
    var
      MyObject: TObject;
    begin
      MyObject := TObject.Create;
    end;
    
    begin
      OnDebugFreeMemFinish := MemFreeEvent;
      Leak;
    end.

What I am missing is the callback like:

    procedure OnMemoryLeak(APointer: PFullDebugBlockHeader);

After browsing the source of FastMM I saw that there is a procedure:

    procedure LogMemoryLeakOrAllocatedBlock(APointer: PFullDebugBlockHeader; IsALeak: Boolean);

which could be overriden, but maybe there is an easier way?


Is there a way to programmatically tell if particular block of memory was not freed by FastMM?

The only thing that I miss about using other editors is finding my place with the mouse. I can look with my eyes to a specific area on the file and with a motion of the mouse and a click I am there. With VIM i have to jjjjjkkkkkkjjjjhhhh... almost there hhhhh oh crap I missed by 3 characters, lll.

I am learning to do marks and i found a bookmarks plugin that is great, I can create markers and destroy them with `&lt;f3&gt;` and navigate to them with &lt;f4&gt; unfortunately the marks are forgotten when the file is closed. 

How do you all super navigate files? I know I could also do 5j7k4j5h and so forth, but there must be a plugin that can read my eyes and put the cursor where I really need it..

I also have learned to use /% to search for a specific term. It does help but all the matching characters are highlighted through out the document.

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What is the basic difference between the following import statements in a Django app?

    import settings

and

    from django.conf import settings




Is there any difference between django.conf.settings and import settings?

What is the basic difference between the following import statements in a Django app?
<pre><code class="hljs language-arduino">import settings
</code></pre>
and
<pre><code class="hljs language-javascript">from django.conf import settings
</code></pre>

I have a string, say: `abc.def.ghi.jkl.myfile.mymethod`. How do I dynamically import `mymethod`?

Here is how I went about it:

    def get_method_from_file(full_path):
        if len(full_path) == 1:
            return map(__import__,[full_path[0]])[0]
        return getattr(get_method_from_file(full_path[:-1]),full_path[-1])
    
    
    if __name__==&#39;__main__&#39;:
        print get_method_from_file(&#39;abc.def.ghi.jkl.myfile.mymethod&#39;.split(&#39;.&#39;))




I am wondering if the importing individual modules is required at all.

Edit: I am using Python version 2.6.5.

Dynamically import a method in a file, from a string

The following code checks if `x` and `y` are distinct values (the variables `x`, `y`, `z` can only have values `a`, `b`, or `c`) and if so, sets `z` to the third character:

    if x == &#39;a&#39; and y == &#39;b&#39; or x == &#39;b&#39; and y == &#39;a&#39;:
        z = &#39;c&#39;
    elif x == &#39;b&#39; and y == &#39;c&#39; or x == &#39;c&#39; and y == &#39;b&#39;:
        z = &#39;a&#39;
    elif x == &#39;a&#39; and y == &#39;c&#39; or x == &#39;c&#39; and y == &#39;a&#39;:
        z = &#39;b&#39;

Is is possible to do this in a more, concise, readable and efficient way?

How can I find the missing value more concisely?

I&#39;m wondering if there&#39;s any way to tell pip, specifically in a requirements file, to install a package with both a minimum version (`pip install package&gt;=0.2`) and a maximum version which should never be installed (theoretical api: `pip install package&lt;0.3`).

I ask because I am using a third party library that&#39;s in active development. I&#39;d like my pip requirements file to specify that it should always install the most recent minor release of the 0.5.x branch, but I don&#39;t want pip to ever try to install any newer major versions (like 0.6.x) since the API is different.  This is important because even though the 0.6.x branch is available, the devs are still releasing patches and bugfixes to the 0.5.x branch, so I don&#39;t want to use a static `package==0.5.9` line in my requirements file.

Is there any way to do that?

How to pip install a package with min and max version range?

How can I calculate the date of the next Friday?

How to calculate next Friday?

I would like to know how to check whether a string starts with &quot;hello&quot; in Python.

In Bash I usually do:

    if [[ &quot;$string&quot; =~ ^hello ]]; then
     do something here
    fi

How do I achieve the same in Python?

Checking whether a string starts with XXXX

I have a model with an optional file field

    class MyModel(models.Model):
      name = models.CharField(max_length=50)
      sound = models.FileField(upload_to=&#39;audio/&#39;, blank=True)

---
Let&#39;s put a value

    &gt;&gt;&gt; test = MyModel(name=&#39;machin&#39;)
    &gt;&gt;&gt; test.save()

---
Why do I get that ?

    &gt;&gt;&gt; test.sound
    &lt;FieldFile: None&gt;
    &gt;&gt;&gt; test.sound is None
    False

---
How can I check if there is a file set ?  


Django - FileField check if None

I have been reading the doc and searching but cannot seem to find a straight answer:

Can you cancel an already executing task? (as in the task has started, takes a while, and half way through it needs to be cancelled)

I found this from the doc at [Celery FAQ][1]

    &gt;&gt;&gt; result = add.apply_async(args=[2, 2], countdown=120)
    &gt;&gt;&gt; result.revoke()

But I am unclear if this will cancel queued tasks or if it will kill a running process on a worker.  Thanks for any light you can shed!



  [1]: http://docs.celeryproject.org/en/latest/faq.html#can-i-cancel-the-execution-of-a-task

Cancel an already executing task with Celery?

suppose we have a model in django defined as follows:

    class Literal:
        name = models.CharField(...)
        ...

Name field is not unique, and thus can have duplicate values. I need to accomplish the following task:
Select all rows from the model that have **at least one duplicate value** of the ``name`` field.

I know how to do it using plain SQL (may be not the best solution):

    select * from literal where name IN (
        select name from literal group by name having count((name)) &gt; 1
    );

So, is it possible to select this using django ORM? Or better SQL solution?



Django select only rows with duplicate field values

I have a very simple query: `select * from tbl1 where title not in(&#39;asdasd&#39;, &#39;asdasd&#39;)`. 

How do I translate that to Django? It&#39;s like I want the opposite of: `Table.objects.filter(title__in=myListOfTitles)`


Django equivalent of SQL not in

I often see people claiming their backend is implemented in Django, but isn&#39;t Django supposed to be for the frontend? I&#39;d assume the backend refers to the business logic where the frontend refers to the presentation. Am I missing something?



Is Django for the frontend or backend?

I&#39;m configuring a Django project that were using the server filesystem for storing the apps static files (`STATIC_ROOT`) and user uploaded files (`MEDIA_ROOT`).

I need now to host all that content on Amazon&#39;s S3, so I have created a bucket for this. Using [`django-storages`](http://readthedocs.org/docs/django-storages/en/latest/) with the `boto` storage backend, I managed to upload collected statics to the S3 bucket:

    MEDIA_ROOT = &#39;/media/&#39;
    STATIC_ROOT = &#39;/static/&#39;
    
    DEFAULT_FILE_STORAGE = &#39;storages.backends.s3boto.S3BotoStorage&#39;
    AWS_ACCESS_KEY_ID = &#39;KEY_ID...&#39;
    AWS_SECRET_ACCESS_KEY = &#39;ACCESS_KEY...&#39;
    AWS_STORAGE_BUCKET_NAME = &#39;bucket-name&#39;
    STATICFILES_STORAGE = &#39;storages.backends.s3boto.S3BotoStorage&#39;

Then, I got a problem: the `MEDIA_ROOT` and `STATIC_ROOT` are not used within the bucket, so the bucket root contains both the static files and user uploaded paths.

So then I could set:

    S3_URL = &#39;http://s3.amazonaws.com/%s&#39; % AWS_STORAGE_BUCKET_NAME
    STATIC_URL = S3_URL + STATIC_ROOT
    MEDIA_URL = &#39;S3_URL + MEDIA_ROOT

And use those settings in the templates, but there is no distinction of static/media files when storing in S3 with `django-storages`.

How this can be done?

Thanks!

How to set-up a Django project with django-storages and Amazon S3, but with different folders for static files and media files?

For the life of me, I have been looking for this everywhere and have not found the answer. I hope I am not posting a duplicate.

It is advised everywhere that you should keep your secret keys in a separate file from your general settings.py. Also, that you should never commit your &quot;secret.py&quot; file that contains keys such as SECRET_KEY, AWS_SECRET_KEY and so on. 

My question is: In your production server, you need to reference your secret keys, that means that your &quot;secret.py&quot; settings file, should live somewhere around the server right? If so, how do you protect your secret keys in production? 

Where to store secret keys DJANGO

I&#39;m reading up that most people do `from django.conf import settings` but I don&#39;t undertstand the difference to simply doing `import settings` in a django project file. Can anyone explain the difference?

What&#39;s the difference between `from django.conf import settings` and `import settings` in a Django project

this is somewhat related to this question  
https://stackoverflow.com/questions/11238514/why-is-djangos-settings-object-a-lazyobject

In my django project i have several applications. Each application can have its own non-trivial settings file.

    proj/
        proj/
             settings.py
        app/
             settings.py
             views.py

What is the general best practice here?  
should app/settings.py do   

    from django.conf import settings
    APP_SETTING= lambda: settings.getattr(&#39;APP_SETTING&#39;, &#39;custom_value&#39;)
    PROJ_SETTING= lambda: settings.PROJ_SETTING

and then in app/views.py do

    import .settings 
    X = settings.APP_SETTING
    Y = settings.PROJ_SETTING

or should I be modifying the django lazy settings object in app/settings.py as per the django coding style?

    from django.conf import settings
    # not even sure how I would check for a default value that was specified in proj/settings.py
    settings.configure(APP_SETTING=&#39;custom_value&#39;)

and then each app/views.py just consumes proj/settings.py via django.conf settings?

    from django.conf import settings
    X = settings.APP_SETTING
    Y = settings.PROJ_SETTING


There are obviously quite a few other permutations but I think my intent is clear.  
Thanks in advance.




django settings per application - best practice?

I was trying to configure my Django project to deploy to Heroku. I am getting the following error and I don&#39;t really know how to fix it. 

Here is the **full traceback** and error:


    22:46:15 web.1  | Traceback (most recent call last):
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/gunicorn/arbiter.py&quot;, line 495, in spawn_worker
    22:46:15 web.1  |     worker.init_process()
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/gunicorn/workers/base.py&quot;, line 106, in init_process
    22:46:15 web.1  |     self.wsgi = self.app.wsgi()
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/gunicorn/app/base.py&quot;, line 114, in wsgi
    22:46:15 web.1  |     self.callable = self.load()
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py&quot;, line 62, in load
    22:46:15 web.1  |     return self.load_wsgiapp()
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py&quot;, line 49, in load_wsgiapp
    22:46:15 web.1  |     return util.import_app(self.app_uri)
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/gunicorn/util.py&quot;, line 354, in import_app
    22:46:15 web.1  |     __import__(module)
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/nirla/wsgi.py&quot;, line 12, in &lt;module&gt;
    22:46:15 web.1  |     from dj_static import Cling
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/dj_static.py&quot;, line 7, in &lt;module&gt;
    22:46:15 web.1  |     from django.contrib.staticfiles.handlers import StaticFilesHandler as DebugHandler
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/django/contrib/staticfiles/handlers.py&quot;, line 8, in &lt;module&gt;
    22:46:15 web.1  |     from django.contrib.staticfiles.views import serve
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/django/contrib/staticfiles/views.py&quot;, line 13, in &lt;module&gt;
    22:46:15 web.1  |     from django.views import static
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/django/views/static.py&quot;, line 96, in &lt;module&gt;
    22:46:15 web.1  |     template_translatable = ugettext_noop(&quot;Index of %(directory)s&quot;)
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/django/utils/translation/__init__.py&quot;, line 65, in gettext_noop
    22:46:15 web.1  |     return _trans.gettext_noop(message)
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/django/utils/translation/__init__.py&quot;, line 52, in __getattr__
    22:46:15 web.1  |     if settings.USE_I18N:
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/django/conf/__init__.py&quot;, line 54, in __getattr__
    22:46:15 web.1  |     self._setup(name)
    22:46:15 web.1  |   File &quot;/Users/nir/nirla/venv/lib/python2.7/site-packages/django/conf/__init__.py&quot;, line 47, in _setup
    22:46:15 web.1  |     % (desc, ENVIRONMENT_VARIABLE))
    22:46:15 web.1  | ImproperlyConfigured: Requested setting USE_I18N, but settings are not configured. You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings.

Here is my **wsgi.py** file:

    import os
    from django.core.wsgi import get_wsgi_application
    from dj_static import Cling
    
    os.environ.setdefault(&quot;DJANGO_SETTINGS_MODULE&quot;, &quot;nirla.settings&quot;) #nirla is the name of the project
    
    
    application = Cling(get_wsgi_application())


And in case it was relevant, my **manage.py** file: 

    import os
    import sys
    
        if __name__ == &quot;__main__&quot;:
            os.environ.setdefault(&quot;DJANGO_SETTINGS_MODULE&quot;, &quot;nirla.settings&quot;)
        
            from django.core.management import execute_from_command_line
        
            execute_from_command_line(sys.argv)


Can anyone seem to understand the issue here? And if so, can you be so kind as to explain what is wrong? 

Content Type	Original Author	Original Content on Stackoverflow
Question	Ozgur Vatansever	View Question on Stackoverflow
Solution 1 - Python	user237076	View Answer on Stackoverflow

Is there any difference between django.conf.settings and import settings?

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Is there a way to programmatically tell if particular block of memory was not freed by FastMM?

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