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Decorator to add placeholders to field

Decorator to automagically add placeholders to form widgets. `cls` can be any class derived from `django.forms.Form` or `django.forms.ModelForm`. The field labels are used as value for the placeholder. This will affect all form instances of this class. * add_placeholders only to forms.TextInput and form.Textarea * add_placeholders_to_any_field adds placeholders to any field Usage: @add_placeholders class Form(forms.Form): name = forms.CharField The name field will render as `<input type="text" placeholder="name">`

  • decorator
  • placeholder
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query builder

""" Takes arguments & constructs Qs for filter() We make sure we don't construct empty filters that would return too many results We return an empty dict if we have no filters so we can still return an empty response from the view """

  • query
  • queryset
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aggregate filter

Makes it possible to add a filtering condition directly after the aggregate function (or possible, `aggregate(expression) WITHIN GROUP (ordering clause)`. This is mostly useful if the annotation has two or more expressions, so it's possible to compare the result with and without the applied filter; it's more compact than using `Case`. It's suggested to add `values` to the queryset to get a proper group by. Usage example: `books = Book.objects.values('publisher__name').annotate( count=Count('*'), filtercount=Filter(expression=Count('publisher__name'), condition=Q(rating__gte=5)) ) ` Supported on Postgresql 9.4+. Possible other third-party backends.

  • filter
  • postgresql
  • olap
  • aggregate
  • expression
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Django chunked queryset iterator

The function slices a queryset into smaller querysets containing chunk_size objects and then yield them. It is used to avoid memory error when processing huge queryset, and also database error due to that the database pulls whole table at once. Concurrent database modification wouldn't make some entries repeated or skipped in this process.

  • django
  • python
  • database
  • queryset
  • iterator
  • memoryerror
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Cachable Django Paginator

This is a modificated version of `CachedPaginator` by **daniellindsley** [https://djangosnippets.org/snippets/1173/](https://djangosnippets.org/snippets/1173/) ([web-arhive-link](https://web.archive.org/web/20150927100427/https://djangosnippets.org/snippets/1173/)). Which not only cache `result_objects`, but the `total_count` of the `queryset` too (usefull if computating the count is an expensive operation too).

  • django
  • cache
  • pagination
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Dead Code Finder

Rough check for unused methods in our apps. Scans models, views, utils, api, forms and signals files for what look like methods calls, then looks at all of our classes' methods to ensure each is called. Do not trust this blindly but it's a good way to get leads on what may be dead code. Assumes a setting called `LOCAL_APPS` so it only bothers to look at the code you've written rather than everything in `INSTALLED_APPS`.

  • refactor
  • cleanup
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Raw include from static dir tag

This is useful when you don't want to put any `{% verbatim %}` tag in the file(s) you're including within template(s) (because you want it/them completely raw) and when you want to load such file(s) from static dir(s), as native `{% include %}` tag can't achieve that (still). Put the provided code in *templatetags/rawinclude.py* in your Django app, and then use it in your template(s) like this: `{% load rawinclude %}{% raw_include 'file.html' %}`

  • include
  • verbatim
  • raw
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Crypt-SHA512 password hasher

Password hashing method using the crypt-sha512 algorithm, To be able to generate password compatible with the crypt-sha512 method avaiable in the standard crypt function since glib2.7 and used on modern linux distros. This provides compatibility with programs and systems that use the glibc crypt library for encrypting passwords (such as shadow passwords used by modern Linux distributions) while providing extra security than the regular crypt-sha1 mechanism (available in Django as CryptPasswordHasher) To use it you just need to add something like this to your django settings file: --- PASSWORD_HASHERS = [ 'utils.hashers.CryptSHA512PasswordHasher', 'django.contrib.auth.hashers.PBKDF2PasswordHasher', 'django.contrib.auth.hashers.PBKDF2SHA1PasswordHasher', 'django.contrib.auth.hashers.BCryptSHA256PasswordHasher', 'django.contrib.auth.hashers.BCryptPasswordHasher', 'django.contrib.auth.hashers.SHA1PasswordHasher', 'django.contrib.auth.hashers.MD5PasswordHasher', 'django.contrib.auth.hashers.UnsaltedSHA1PasswordHasher', 'django.contrib.auth.hashers.UnsaltedMD5PasswordHasher', 'django.contrib.auth.hashers.CryptPasswordHasher', ] --- You need to keep the standard hashers on the list to be able to convert existing passwords to the new method. The next time a user login after the modification the password will be converted automatically to first hasher on the list. Thanks mmoreaux for his improvements!!

  • password
  • hash
  • crypt
  • sha512
  • 1.9
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Generate iCal VTIMEZONE block with DAYLIGHT and STANDARD components, based on pytz zoneinfo data

In the last few days I spent a lot of time trying to find a library or repository of some kind that could help me generate the required DAYLIGHT and STANDARD components of ical VTIMEZONE blocks. Since I couldn't find anything, I cobbled together this snippet to poke around in pytz timezone information and output the bare minimum I needed to make my ICS files compliant and useful (DST transitions for this year and the next). I promise it's (superficially) tested against "real" ICS files, but that's all. UPDATE: Thanks to @ariannedee for a much improved version (see comment for details)

  • pytz
  • timezones
  • ical
  • icalendar
  • ics
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Django EncryptedField

Inspired by [Base64Field: base64 encoding field for storing binary data in Django TextFields](https://djangosnippets.org/snippets/1669/) but in a generic way. from django.db import models import base64 class Base64Encryptor(object): def encrypt(self, value): return base64.encodestring(value) def decrypt(self, msg): return base64.decodestring(msg) class MyModel(models.Model): ... b64_data = EncryptedField(encryptor=Base64Encryptor) ... # Usage my_obj = MyModel() my_obj.b64_data = "hello" print(my_obj.b64_data) # will output 'hello' print(my_obj.b64_data_enc) # will output 'aGVsbG8=\n'

  • django
  • fields
  • encryption
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