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All snippets written in Python

2957 snippets

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Test and Restart Memcached Server

Request-phase cache middleware that checks to make sure the Cache server is running. Starting it if it is not. This is run for every request, it checks to see if it can get a defined item out of the cache, if that fails it tries to set it. Failing that it decides the server is probably crashed, so goes though and attempts to connect to the server. Failing a connection it will launch a new server. This is probably not useful on large scale multi server deployments as they likely have their own testing for when services crash, but I am using it in a shared hosting environment where I have to run my own copy of memcache manually and cannot setup proper services testing, so I use this to just make sure the cache server is still running.

  • middleware
  • cache
  • memcached
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Retrieve human-readable value from choices tuple or value from dict

Will help you retrieve the value from a dictionary with a supplied key, or the human-readable value from a choices tuple. Works as follows: To retrieve the value of a dict: `{{ crime_rates_dict|getval:"Chicago" }}` <-- will return value of `crime_rates_dict["Chicago"]` To retrieve the human-readable value from a choices tuple: `{{ country.COUNTRIES|getval:"US" }}` <-- will return "United States" in `COUNTRIES = (("US", "United States"),)`

  • template
  • templatetag
  • choices
  • dict
  • tuple
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Git Revision Template Tag

This displays the short commit id from the current HEAD. Add this to your admin/base_site.html or any other template. {% block userlinks %} /&nbsp;HEAD: <span style="color:yellow">{% git_short_version %}</span> /&nbsp; {{ block.super }} {% endblock %}

  • git
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Drag and drop ordering of admin list elements using jQuery UI

Adds drag-and-drop ordering of rows in the admin list view. The only requirements is that the model has a field holding the position and that the field is made list_editable in the ModelAdmin. The changes of the ordering are applied after clicking 'Save'. The included javascript uses [jQuery UI's sortable](http://jqueryui.com/demos/sortable/) plugin Inspired by snippets [#1053](http://djangosnippets.org/snippets/1053) and [#998](http://djangosnippets.org/snippets/998/). Another similar snippet using AJAX is [#2047](http://djangosnippets.org/snippets/2047/).

  • admin
  • sort
  • jquery
  • order
  • sortable
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JSONField

This is a great way to pack extra data into a model object, where the structure is dynamic, and not relational. For instance, if you wanted to store a list of dictionaries. The data won't be classically searchable, but you can define pretty much any data construct you'd like, as long as it is JSON-serializable. It's especially useful in a JSON heavy application or one that deals with a lot of javascript. **Example** (models.py): from django.db import models from jsonfield import JSONField class Sequence(models.Model): name = models.CharField(maxlength=25) list = JSONField() **Example** (shell): fib = Sequence(name='Fibonacci') fib.list = [0, 1, 1, 2, 3, 5, 8] fib.save() fib = Sequence.objects.get(name='Fibonacci') fib.list.append(13) print fib.list [0, 1, 1, 2, 3, 5, 8, 13] fib.get_list_json() "[0, 1, 1, 2, 3, 5, 8, 13]" *Note:* You can only save JSON-serializable data. Also, dates will be converted to string-timestamps, because I don't really know what better to do with them. Finally, I'm not sure how to interact with forms yet, so that realm is a bit murky.

  • models
  • model
  • json
  • db
  • field
  • json-field
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Admin: ordering by multiple fields in a column sort

The new changelist supports clicking on a column header to order by that column, like iTunes. Unlike iTunes, which sorts by track number if you click the Artist or Album column header, it can only order by the column clicked on. By adding a property to my ModelAdmin, and subclassing ChangeList, I was able to make it also sort by track number when sorting by Artist or Album. [Blog post](http://python-web.blogspot.com/2010/07/sorting-by-more-than-one-field-in-admin.html) [Repository with full example](http://github.com/benatkin/tuneage)

  • admin
  • ordering
  • changelist
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TableSelectMultiple Widget

A widget for selecting from a list of `Model` instances using `MultipleChoiceField` which renders a table row for each choice, consisting of a column for a checkbox followed by a column for each item specified in `item_attrs`, which must specify attributes of the objects passed as choices.

  • forms
  • table
  • widget
  • selectmultiple
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Better debugging mail server

Python includes (and [Django recommends](http://docs.djangoproject.com/en/dev/topics/email/?from=olddocs#testing-e-mail-sending)) a simple email debugging server which prints mail to stdout. The trouble is, unlike any half-competent mail reader, long lines are broken up, and thus long URLs don't work without modification. This snippet simply unwraps long lines (broken by "=") so long URLs can be easily copied/pasted from the terminal. Save this snippet into a file named "better.py" and execute it.

  • mail
  • debuggingserver
  • long-lines
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Dynamic Test Loading

Ok... this is really a hack. But I love it. I hate setting up all of my test cases into suites, and making sure that I remember to add them each time I add a new python file... annoying! This allows me to have a tests package and then just add python files and packages to that test package (mirroring my app setup). Each of the files are then dynamically imported and every test case is automatically executed. If you don't want one to execute, add it to the ignore list. If you add 'views' to the ignore list, it will ignore all views, otherwise you would have to specify 'package.views' if it is in a package. So... in short this is a bit ghetto, but it saves me a lot of time just setting up all my tests... now I can just write them! Hope it's useful to someone. Greg

  • dynamic
  • unittest
  • load
  • test
  • loader
  • loading
  • unit
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Automatically generate admin

A management command to automatically generate a fully specified admin for the models in a specific app. It automatically generates raw_id_fields, search_fields, list_filter and more. It bases this on date fields, fields named as "name" or slug. Usage: ./manage admin_autogen <model>

  • django
  • scaffold
  • auto
  • django-admin
  • automatic
  • generation
  • generate
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Optimistic locking in Admin

Look here: https://bitbucket.org/depaolim/optlock The snippet of Marco De Paoli is much better than this one! :-) ========================================================= If two users save same record, the second one will overwrite first one. Use this snippet to achieve an optimistic locking, so the second user will get an exception. Save the snippet in optlock.py and put it anywhere in your pythonpath. **Do not put _version_opt_lock in readonly_fields** or the snippet will fail! (if you need to hide it, use jquery). The snippet need in request.POST the original value of _version_opt_lock and if you make it a readonly field Django doesn't POST its value. When this [bug](https://code.djangoproject.com/ticket/11277) will be fixed it should be possible to use a hiddeninput widget. models.py example: ... import optlock ... class YourModel(optlock.Model): ... admin.py example: ... import optlock ... class YourModelAdmin(optlock.ModelAdmin): ... That's it :-)

  • admin
  • locking
  • optimistic locking
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Amazon S3 browser-based upload form(FIXED)

This is a 'fixed' version of snippet [1868](http://djangosnippets.org/snippets/1868/) Changes: *Correctly handle the Content-Type, because amazon requieres it to be named with a dash and we can't use dashes in the form attributes declaration. *Also added max_size handling, with the corresponding update to the policy generation. *Added an example usage with some javascript for basic validation. [See the amazon reference](http://aws.amazon.com/articles/1434?_encoding=UTF8&jiveRedirect=1)

  • s3
  • amazon
  • html form
  • upload form
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Alphabetic filter for admin

This snippet is based on [#748](http://www.djangosnippets.org/snippets/748/). Adds filtering by first char (alphabetic style) of values in the admin filter sidebar. The example below results in this filter: By name that starts with All A B G M X urls.py example (only for register the filter): import <your project>.admin.filterspecs models.py example: from django.db import models class Person(models.Model): name = models.CharField(max_length=40) name.alphabetic_filter = True admin.py example: class Admin: list_filter = ['name']

  • filter
  • admin
  • filterspec
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