Tutorial

Here you will learn how to become fluent inrepocket in just a couple of minutes.

Installing

pip install repocket

Configuring the connection

Repocket uses a global connection pool where all the connections will be shared when possible.

In your application code you will have to configure how repocket connects, but you will do it only once, to show you how, imagine that this is your own application code:

>>> from repocket.connections import configure
>>> configure.connection_pool(hostname='myredis.cooldomain.com', port=6379, db=0)

# at this point you're ready to use your declared models

Declaring Models

Repocket provides a model interface that looks just like Django, but the field types are super simplified.

Here is how you declare a model:

>>> from repocket import attributes
>>> from repocket import ActiveRecord
>>>
>>>
>>> class User(ActiveRecord):
...     name = attributes.Unicode()
...     house_name = attributes.Unicode()
...     email = attributes.Bytes()
...     password = attributes.Bytes()
...     metadata = attributes.JSON()

If you were in Django you would then need to run syncdb to have a SQL table called User with the declared fields. But this ain’t Django, ight?

At this point you are ready to start saving user data in redis.

By default the attributes of the your model are actively saved in a hash redis datastructure.

Repocket currenty also supports another attribute called ByteStream that will seamlessly store the value in a string, so that you can APPEND more bytes to it with a single call.

But we will get there soon enough, for now let’s understand how to save a new user and how it will be saved inside of redis.

Persisting Data

Let’s save a User instance in redis:

>>> import bcrypt

>>> harry = User.create(
...     id='970773fa-4de1-11e5-86f4-6c4008a70392',
...     name='Harry Potter',
...     email='harry@hogwards.uk',
...     house_name='Gryffindor',
...     password=bcrypt.hashpw(b'hermione42', bcrypt.gensalt(10)),
...     metadata={
...         'known_tricks': [
...             "Protego",
...             "Expelliarmus",
...             "Wingardium Leviosa",
...             "Expecto Patronum"
...         ]
...     }
... )
>>> ron = User.create(
...     id='40997aa4-71fc-4ad3-b0d7-04c0fac6d6d8',
...     name='Ron Weasley',
...     house_name='Gryffindor',
...     email='ron@hogwards.uk',
...     password=bcrypt.hashpw(b'hermione42', bcrypt.gensalt(10)),
...     metadata={
...         'known_tricks': [
...             "Protego",
...             "Expelliarmus",
...         ]
...     }
... )

Retrieving an item by its id

>>> harry = User.objects.get(id='970773fa-4de1-11e5-86f4-6c4008a70392')
>>> harry.metadata
{
    'known_tricks': [
        "Protego",
        "Expelliarmus",
        "Wingardium Leviosa",
        "Expecto Patronum"
    ]
}

Manipulating in-memory data

You can get the valus of an instance with either .attribute` notation or ["attribute"].

>>> harry = User.objects.get(id='970773fa-4de1-11e5-86f4-6c4008a70392')
>>> harry.id
UUID('970773fa-4de1-11e5-86f4-6c4008a70392')

>>> harry['id']
UUID('970773fa-4de1-11e5-86f4-6c4008a70392')

Deleting a record from redis

The delete() method returns an integer corresponding to the number of redis keys that were deleted as result.

>>> harry = User.objects.get(id='970773fa-4de1-11e5-86f4-6c4008a70392')
>>> harry.delete()
1

Retrive multiple items with filter

>>> results = User.objects.filter(house_name='Griffindor')
>>> len(results)
2
>>> results[0].name
'Harry Potter'
>>> results[1].name
'Ron Weasley'

Note

The order in which the elements are returned by filter() cannot be guaranteed because the id is a uuid. Use the .order_by() method

The filter() method returns a ResultSet object, which is a list with superpowers. The main superpower is the ability to order the results.

>>> results = User.objects.filter(house_name='Griffindor').order_by('-name')
>>> len(results)
2
>>> results[0].name
'Ron Weasley'
>>> results[1].name
'Harry Potter'