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All snippets written in Python

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Generate Model Data. Lots of Options.

Generate model data with this django management command! Data is generated based off of the model field types. And will also correctly generate foreign key's to other randomly generated records for join tables. And generate images with random colors and random words in the image - for image fields. You can supply quite a few parameters that control how the data is generated. And you can control it per field, per model. Or you can supply your own callable function which you can return your own random data. **SEE THE DOCS / EXAMPLE IN THE CODE SNIPPET FOR AVAILABLE OPTIONS, AND HOW TO CONTROL GENERATED DATA PARAMETERS** You can generate data that looks like real content, without having to write fixtures and such. Just generate it! It can generate data for these types of fields: EmailField SlugField BooleanField DateField DateTimeField TimeField IntegerField DecimalField TextField CharField IPAddressField URLField SmallIntegerField PositiveSmallIntegerField PositiveIntegerField ImageField There are also a few callables included that you can use to generate this kind of data: zip, extended zip, hashkey and uuid It's also worth noting that I keep this project up to date on my own git repository. There are a few fonts you'll need if you want to generate imaages, included in my git repo. http://gitweb.codeendeavor.com/?p=dilla.git;a=summary

  • model
  • random
  • data
  • management
  • command
  • lipsum
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Complex Formsets, Redux

Background ========== Two years ago, Malcolm Tredinnick put up an excellent post about doing dynamic Django forms. There have been several excellent write-ups on it since - Google is your friend. One year ago, I attempted to make a dynamic Formset - see [this snippet](http://www.djangosnippets.org/snippets/1290/). Malcolm posted a cleaner solution two weeks later, and I liked his solution better. Some time after that happened, his site tanked. I'm re-posting my snippet using his technique, so that everyone can see how it is done. Credit to goes to Malcolm - I'm just the messenger. If his site ever comes back up , check out his complex formset post [here](http://www.pointy-stick.com/blog/2009/01/23/advanced-formset-usage-django/). I'll use Malcolm's example code, with as few changes as possible to use a formset. The models and form don't change, and the template is almost identical. I won't reproduce all of Malcolm's code - I'm just show the form setup. There are no models here - you'll have to use your imagination for Quiz, Question, and Answer models. He did some fancy validation as well - I'm not going to here. Problem ======= Build a formset based on dynamically created forms. Solution ======== The core idea in this code is found in the `_construct_form` method. Typically, this is where a formset makes new forms - it handles indexing them so that everything is nice and unique. We can take advantage of this by overriding the method and inserting a `kwarg` that will be passed on to our form class, then calling the parent `_contruct_form` method to let it finish doing everything else for us. This is what Malcolm, a core Django developer, knows about, and I, a random Django user, typically do not. Code ==== This pattern greatly simplifies building formsets dynamically, and it really only requires a few bits of knowledge. 1. If we `pop()` special arguments out of `kwargs` dictionaries, we then can pass the remaining `kwargs` along to parent methods and let them do the rest of the setup for us. See code tricks #1 and #3. 2. If we have a form and need to add dynamic fields that we didn't declare the usual way, we can just add them to the `self.fields` dictionary. See code trick #2. 3. If we need to add forms dynamically to a formset, we can use the `self.extra` variable to specify how many we want, based on the length of a custom queryset. See code trick #4. 4. If we want to pass some special arguments to a form that will be part of a formset when it is constructed, we can add them to the `kwargs` dict in `_construct_form`, taking advantage of the `index` variable to track which object from our queryset we wanted. See code trick #5.

  • dynamic
  • formset
  • complex
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SearchableManager

A drop-in chainable manager for providing models with basic search features such as +/- modifiers, quoted exact phrases and ordering by relevance.

  • search
  • model
  • manager
  • queryset
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Get admin url for a model

Add this to your model to be able to get their admin change link from anywhere Useful if you want to jump to the admin screen of an object you are looking at on the front end

  • admin
  • url
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Dynamically create Django admin actions

With this snippet, I made a set of admin actions for assigning `Quality` objects to `Package` objects. The Django docs for [ModelAdmin.get_actions][1] explain the dictionary of tuples that is returned. [1]: http://docs.djangoproject.com/en/1.1/ref/contrib/admin/actions/#django.contrib.admin.ModelAdmin.get_actions

  • admin
  • admin-actions
  • closures
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Technical 500 by group membership

Based loosely on [Eric's middleware](http://ericholscher.com/blog/2009/sep/5/debugging-django-production-revisited/), this middleware will show the technical 500 page (which you'd get if DEBUG == True) to any user who is (1) superuser and (2) a member of the settings.TECHNICAL_500_GROUP_NAME group. (If no setting exists, 'Technical Errors' is the presumed group name. I agreed with the comments that caching should be unnecessary given the (presumptive) edge case of exception + superuser. Assuming you don't have tons of superusers, this code is a good bit simpler.

  • admin
  • user
  • auth
  • debugging
  • 500
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Persistent connection to PostgreSQL database

Hi, I made some small custom psycopg2 backend that implements persistent connection using global variable. With this I was able to improve the amout of requests per second from 350 to 1600 (on very simple page with few selects) Just save it in the file called base.py in any directory (e.g. postgresql_psycopg2_persistent) and set in settings DATABASE_ENGINE to projectname.postgresql_psycopg2_persistent This code is threadsafe, however because python don't use multiple processors with threads you won't get bit performance boost with this one. I really recommend using it in daemon mode. In apache mod_wsgi just set processes=8 threads=1

  • database
  • connection
  • persistent
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Enhancing template tags with "as variable" syntax

Add the decorator to an already defined templatetag that returns a Node object: @with_as def do_current_time(parser, token): ... return a_node The decorator will patch the node's render method when the "as" syntax is specified and will update the context with the new variable. The following syntaxes are available: {% current_time %} {% current_time as time %} {{ time }}

  • templates
  • templatetags
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CSV to JSON Fixture

**This script converts a CSV file into a JSON file ready to be imported via `manage.py loaddata` like any other fixture data.** It can be used manually to do a one-time conversion (for placing into a /fixtures folder), or used in a fabric script that automatically converts CSV to JSON live then runs `loaddata` to import as fixture data. To run script: >`csv2json.py input_file_name model_name` > >e.g. csv2json.py airport.csv app_airport.Airport > >Note: input_file_name should be a path relative to where this script is. **Scripts depends on simplejson module.** The module can just be placed in a sub-folder to the script to make it easy to import. If you use the same Python binary that you use for your Django site, you could use the Django import instead: `from django.utils import simplejson` **File Input/Ouptut formats:** Assumes CSV files are saved with LF line endings, and that first line has field values. First column is the model's pk field. Sample CSV input: id,ident,name,city,state 1,00C,Animas Air Park,Durango,CO 6,00V,Meadow Lake,Colorado Springs,CO 7,00W,Lower Granite State,Colfax,WA 12,01J,Hilliard Airpark,Hilliard,FL Output file name is input name + ".json" extension. Sample JSON output: [ { "pk": 1, "model": "app_airport.Airport", "fields": { "name": "Animas Air Park", "city": "Durango", "ident": "00C", "state": "CO", } } ] **Debugging Conversion Problems** If JSON import errors out with "ValidationError: This value must be an integer", you probably have a blank in an Integer field within your CSV file, but if can't figure out, try setting a breakpoint in file: ./django/django/db/models/fields/__init__.py e.g. 688 try: 689 return int(value) 690 except (TypeError, ValueError): 691 import pdb; pdb.set_trace() 692 -> raise exceptions.ValidationError( 693 _("This value must be an integer.")) To figure out what field caused the error, while in the debugger: (Pdb) u <- to go UP the callstack (Pdb) field.name

  • json
  • loaddata
  • fixtures
  • csv
  • import
  • fixture
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EmailListField for Django

A simple Django form field which validates a list of emails. [See this at my blog](http://sciyoshi.com/blog/2009/aug/08/emaillistfield-django/)

  • fields
  • forms
  • email
  • form
  • field
  • email-list
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Google Analytics Template Tag

Includes the Javascript for Google Analytics. Will not show Google Analytics code when DEBUG is on or to staff users. Use {% googleanalyticsjs %} in your templates. You must set something like GOOGLE_ANALYTICS_CODE = "UA-1234567-1" in your settings file. Assumes 'user' in your template variables is request.user, which it will be if you use: return render_to_response('template.html',{ }, context_instance=RequestContext(request)) (Assuming django.core.context_processors.auth is in TEMPLATE_CONTEXT_PROCESSORS, which it is by default)

  • google
  • urchin
  • analytics
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More readable Enumeration class for Django choices

We currently use two-level tuples to specify choices of a field in models or forms. But, because it has only (value, verbose name) pair, the readability is bad whenever we indicate a specific choice value in our Python codes. So I made a small class that does "magic" for this: A Named Enumeration. Instead of `myobj.status == 0`, use `myobj.status == STATUS.UNREVIEWED`, for example.

  • choices
  • model
  • orm
  • enumeration
  • enum
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format output as table

Ever wished you could have pretty SQL-like output for a python object (e.g., a list of dicts) while you're debugging your code? This function will do just that. Simply pass it an object that is an iterable of dictionaries and it returns it in an easy-to-read table, similar to the output of commandline SQL. Example: from tablelize import tableize from django.contrib.auth.models import User print(tableize(User.objects.values('email', 'first_name', 'last_name'))) +------------+-----------+-------------------+ | first_name | last_name | email | +------------+-----------+-------------------+ | Test | User | [email protected] | | Another | User | [email protected] | +------------+-----------+-------------------+

  • format
  • table
  • output
  • tablize
  • tableize
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Django Class Views

After using Zope3/Grok for a little, I wondered how hard it would be to implement views as classes in Django, in a similar vain to how it's done in Grok. I came up with something rather simple but effective. It may be more appropriate if you use a template engine other than Django Templates, which allows you to call functions with arguments, but it's still useful none-the-less to encapsulate functions in a class. You could, for example, extend View to be JinjaView, just replacing render_template(). A nice extension, I imagine, would be to automatically figure out the template name as well as the path prefix for it (since you probably want it to be found under packagename/templatename.html).

  • django
  • view
  • class
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Author: rmt
  • 4
  • 6