Attach metadata to any Django models using redis
Project description
Attach metadata to any Django models using redis.
Installation
Either check out the package from GitHub or it pull from a release via PyPI:
pip install django-metadata
Usage
With django-metadata you can attach metadata to any Django models, you will be able to link keys and theirs values to any instances.
Currently only Redis is supported with only redis-py as backend.
Let’s say you have this model:
# models.py from django.db import models class User(models.Model): username = models.CharField(max_length=150)
Now you have to attach the MetadataMixin to your model:
# models.py from django.db import models from metadata.mixins import MetadataMixin class User(MetadataMixin, models.Model): username = models.CharField(max_length=150)
You can customize the way django-metadata is storing your values by providing a metadata_key property to your model:
# models.py from django.db import models from metadata.mixins import MetadataMixin class User(MetadataMixin, models.Model): username = models.CharField(max_length=150) def metadata_key(self): return 'metadata:utilisateur:%d' % self.pk
By default, the schema will be metadata:%(lowerclassname)s:%(primary_key)s.
Now we have connected our model to the mixin we can play with the API.
The API of MetadataContainer follows the same principes as dict.
Adding keys
>>> from myapp.models import User >>> user = User.objects.create(username='thoas') >>> user.metadata['mail_signup_sent'] = 1 >>> user = User.objects.get(username='thoas') >>> user.metadata['mail_signup_sent'] 1 >>> user.metadata = {'mail_signup_sent': 0} >>> user.metadata['mail_signup_sent'] 0
Removing keys
You can either removing a key by setting its value to None or use the del operator.
>>> del user.metadata['key'] >>> user.metadata['key'] Traceback (most recent call last): ... KeyError: 'key' >>> user.metadata.get('key', None) None >>> user.metadata['foo'] = 'bar' >>> user.metadata['foo'] = None >>> user.metadata['foo'] Traceback (most recent call last): ... KeyError: 'foo' >>> user.metadata.get('foo', None) None >>> user.metadata['key'] = 'value' >>> user.metadata['foo'] = 'bar' >>> user.metadata = {'foo': None} >>> user.metadata['foo'] Traceback (most recent call last): ... KeyError: 'foo' >>> user.metadata['key'] value
Iterating keys
>>> 'value' in user.metadata True >>> user.metadata.values() ['value'] >>> user.metadata.keys() ['key'] >>> user.metadata.items() [('key', 'value')]
Incrementing keys
As we are using Redis as storing engine you can use some of its nice features:
>>> user.metadata.incr('counter') >>> user.metadata['counter'] 1 >>> user.metadata.incr('counter', 2) >>> user.metadata['counter'] 3
Inspiration
django-metadata comes from an original idea of twidi.
Project details
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