bloop 0.9.13

ORM for DynamoDB

DynamoDB object mapper for python 3.4+

Installation

pip install bloop

Usage

Define some models:

import arrow
import uuid
from bloop import (Engine, Column, Integer, DateTime, UUID,
                   GlobalSecondaryIndex, String, new_base)
Base = new_base()
engine = Engine()


class Account(Base):
    class Meta:
        read_units = 5
        write_units = 2

    id = Column(UUID, hash_key=True)
    name = Column(String)
    email = Column(String)
    by_email = GlobalSecondaryIndex(
        hash_key='email', projection='keys_only',
        write_units=1, read_units=5)


class Tweet(Base):
    class Meta:
        write_units = 10
    account = Column(UUID, hash_key=True)
    id = Column(String, range_key=True)
    content = Column(String)
    date = Column(DateTime)
    favorites = Column(Integer)

    by_date = GlobalSecondaryIndex(
        hash_key='date', projection='keys_only')

engine.bind(base=Base)

Create an instance:

account = Account(id=uuid.uuid4(), name='@garybernhardt',
                  email='[e-mail]')
tweet = Tweet(
    account=account.id, id='600783770925420546', date=arrow.now(),
    content=(
        'Consulting service: you bring your big data problems'
        ' to me, I say "your data set fits in RAM", you pay me'
        ' $10,000 for saving you $500,000.'))

engine.save([account, tweet])

Query or scan by column values:

email = '[e-mail]'
yesterday = arrow.now().replace(days=-1)

account = engine.query(Account.by_email)\
               .key(Account.email == email).first()
tweets = engine.query(Tweet)\
               .key(Tweet.account == account.id)

for tweet in tweets.filter(Tweet.date >= yesterday):
    print(tweet.content)

Versioning

• bloop follows semver for its public API.

  • You should not rely on the internal api staying the same between minor versions.

  • Over time, private apis may be raised to become public. The reverse will never occur.

Contributing

Contributions welcome! Please make sure tox passes (including flake8) before submitting a PR.

Development

bloop uses tox, pytest, coverage, and flake8. To get everything set up with pyenv:

# RECOMMENDED: create a virtualenv with:
#     pyenv virtualenv 3.4.3 bloop
git clone https://github.com/numberoverzero/bloop.git
pip install tox
tox