README.rst

django-dict

Django dict is model transformer. When you use JSON's or just need some dicts, you can just do obj.to_dict() and it will fetch objects and format them. More docs are in doc strings in ToDictClass.

Example

import todict
from django.db import models

# Example from django docs + todict
class Musician(models.Model, todict.ToDictClass):
    first_name = models.CharField(max_length=50)
    last_name = models.CharField(max_length=50)
    instrument = models.CharField(max_length=100)

class Album(models.Model, todict.ToDictClass):
    artist = models.ForeignKey(Musician)
    name = models.CharField(max_length=100)
    release_date = models.DateField()
    num_stars = models.IntegerField()

# And what we can do now

musician = Musician.objects.all()[0]

# return as dict
>>> musician.to_dict()
{
    'id': 0,
    'first_name': 'Bla',
    'last_name': 'Ble',
    'instrument': 'guitar',
    'album': [1,5]
}

# return only selected fields
>>> musician.to_dict("first_name")
{
    'first_name': 'Bla'
}

# return all fields exluding some
>>> musician.to_dict("-first_name")
{
    'id': 0,
    'last_name': 'Ble',
    'instrument': 'guitar',
    'album': [1,5]
}

# fetch related objects and select fields from them
>>> musician.to_dict("first_name album! album|name")
{
    'first_name': 'Bla'
    'album': [{'name': 'first album'}, {'name': 'second album'}]
}

# filter related objects
>>> musician.to_dict("first_name album(name__startswith=second)! album|name")
{
    'first_name': 'Bla',
    'album': [{'name': 'second album'}]
}

# move data
>>> musician.to_dict("first_name album(name__startswith=second)! album|!0|name:album_name")
{
    'first_name': 'Bla',
    'album': [{}],
    'album_name': 'second album'
}

# delete keys after processing
>>> musician.to_dict("first_name album(name__startswith=second)! album|!0|name:album_name ~album")
{
    'first_name': 'Bla',
    'album_name': 'second album'
}

# rename keys
>>> musician.to_dict("first_name=>name")
{
    'name': 'Bla'
}

And it all works on normal dicts.

import todict
my_dict = todict.FormatedDict({'a': 1, 'b': {'c': 'd', 'e': {'f'}}})

>>> my_dict.to_dict('a')
{
    'a': 1
}

# but my_dict is still the same
>>> my_dict
{'a': 1, 'b': {'c': 'd', 'e': {'f'}}}

# and like in django examples, but without fetch feture, you can move, copy, delete, exclude, etc.

TODO or wish list

• Tests - it is already tested in a quite big app, but it would be nice to have own specyfic test cases for this lib.
• Performance - there is nothing to complain, but in future maybe some optional low level dict operations or format parsing tools would be written.
• Better fetch - fetch is complicated, current version don't support fetching twice same field with another set of filters.
• Using prefetched data - look at my another projects
• Better format parsing - there is some pyparse parsing in alfa version with some nice fetures, but not fully working - maybe in some time

WARNINGS

• fetch has it's own humors, for our cases it's working, but you can have problems with spaces in filter arguments witch are not allowed for now.
• you can fetch field in fetch in fetch, but it's not very performant way of getting data especially when using filters (no prefetches)
• it's addictive and can save too much of your time ;) We ended with to_dicts everywhere.
• look in the docs for special hooks and cases.