Login

All snippets written in Python

2957 snippets

Snippet List

Clear FileField/ImageField files in the Admin

The widget for FileField and ImageField has a problem: it doesn't supports clear its value and it doesn't delete the old file when you replace it for a new one. This is a solution for this. It is just for Admin, but you can make changes to be compatible with common forms. The jQuery code will put an **<input type="checkbox">** tag next to every **<input type="file">** and user can check it to clear the field value. When a user just replace the current file for a new one, the old file will be deleted.

  • admin
  • jquery
  • imagefield
  • filefield
Read More

Real shuffle function

This function solve the issue of random.shuffle that is based only on randomized shuffling (that's not a real shuffling, because many times items returned aren't shuffled enough). This function make a randomized shuffle and after this loops long the list resorting to avoid two items with a same value in a given attribute. When shuffling is over and there are duplicates, they are leftover to the end (and you can remove them if you set 'remove_duplicates' to True) Run it in a separated file to see it in action.

  • shuffle
Read More

PermanentRedirectMiddleware

This is a simple middleware that redirects the exactly URL requested with the correct domain. It is useful when you have more than one domain (most of cases with "www." or IP) to access a website. To make it works, download the snippet file as the name "permanent_redirect.py" and add its path as the first item in MIDDLEWARE_CLASSES setting in settings.py. Later you must inform a setting called `HTTP_HOST_DOMAIN` with the correct domain.

  • middleware
  • redirect
  • permanent
  • seo
Read More

RequestFactory: Easily create mock request objects, for use in testing

Django's testing framework assumes you will be running your tests against "live" views that have been plugged in to your site's URL configuration - but sometimes you might want to run a test against a view function without first wiring it in to the rest of the site. This class makes it easy to do that by providing a "factory" for creating mock request objects, re-using the existing test Client interface (and most of the code). Once you've created a request object in your test you can use it to call your view functions directly, then run assertions against the response object that gets returned.

  • testing
  • httprequest
Read More

Switch/case tags.

Meant mostly as a demo of how to do complex block tags, here's a switch/case implementation. It's deliberately simplistic: no default cases, no multiple values for the same case, etc. This is so that you can focus on the technique. Pay particular attention to how both switch and case pull out their child nodes and save them for later rendering. This is a very useful technique for these types of "structured" template tags.

  • templatetag
  • switch
  • case
  • flow
  • logic-doesnt-belong-in-templates
Read More

Profiling middleware using cProfile

Similar to [Profiling Middleware](http://www.djangosnippets.org/snippets/186/), but uses cProfile instead of hotshot. Append ?prof to the URL to see profiling output instead of page output.

  • middleware
  • performance
  • profiler
Read More
Author: sgb
  • 5
  • 24

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
Read More

Encrypted Custom Model Field

Custom model field to support two ways encryption. The key is provided in the app settings.py file. It should be at least 32 chars. ** usage ** Assuming that you placed the new code into fields.py from app.fields import EncyptedField class Account(models.Model): password = EncryptedField()

  • custom-model-field
  • encrypted
Read More

Loading initial data per model at table creation (useful with migrations)

A very simple way of automatically loading data on model creation. As I am using South I wanted an automatic way of loading initial data only when a new model is create during a migration. Django provides almost everything out of the box by providing the *post_syncdb* signal (triggered also by South migrate command) and the *loaddata* command. The code will simply look for a an existing fixture named `<model>_initial.*` and invoke the *loaddata* command to try to load it Note: beware *post_syncdb* signal is deprecated since version 1.7: it has been replaced by *post_migrate*.

  • loaddata
  • migration
  • south
Read More

Text Highlighting Filter

This filter can be used to wrap <span class='highlight'> around anything you want to highlight in a block of text. For example, if you had 'foo bar foo baz' inside the context variable MYTEXT, you could do {{ MYTEXT|highlight:'foo' }}, and "<span class='highlight'>foo</span> bar <span class='highlight'>foo</span> baz" would be returned. How you style the highlight class is up to you.

  • filter
  • text
  • highlight
Read More