SQLAlchemy-Norm 0.0.5

Normalize SQLAlchemy Object to Plain dict and list

Working in Progress. Normalize SQLAlchemy Object to Plain dict and list. Convert SQLAlchemy to Dict without pain!

pip install sqlalchemy-norm

An example of a simple code:

from yourapp.database import Base, session
from sqlalchemy_norm import Normalizable

class User(Base, Normalizable):
    # ...

me = User('Edward')
norm = me.vars() # {"name": "Edward"}

users = session.query(User).all()
norms = [user.vars() for user in users]
"""
[
    {"name": "Edward"},
    {"name": "Koala"},
    {"name": "Kangaroo"}
]
"""

If you like,

python setup.py test

Why?

When I tried to convert from SQLAlchemy object to JSON, it’s not an easy job than I expected. If SQLAlchemy objects could convert to plain objects, it will be better to handle it for most of converting situations, jsonify in Flask, especially.

Contributing

I’m not good at python and I don’t know pythonic code that much. If you have any idea or opinion about the code, please leave an issue on the issue tracker. Contributing the code is always welcome.

License

This software is licensed under the New BSD License. See the LICENSE file in the top distribution directory for the full license text.

Usage

Simple Model

In model,

from datetime import datetime

from sqlalchemy import Column, Integer, String, DateTime
from sqlalchemy_norm import Normalizable

from yourapp.database import Base


class User(Base, Normalizable):
    __tablename__ = 'users'

    id = Column(Integer, primary_key=True)
    name = Column(String)
    nickname = Column(String)
    password = Column(String) # do not save password as plain string
    point = Column(Integer)
    created_at = Column(DateTime)

    # specify your dict strcutrue inside the model
    __excludes__ = ['password']
    __includes__ = ['display_name']

    @property
    def display_name(self):
        return "%s (%s)" % (self.nickname, self.name)

    def __init__(self, name, nickname=None, created_at=datetime.now()):
        self.name = name
        self.nickname = nickname
        self.created_at = created_at

Now we can use it like below:

from models import User

me = User("Edward", "haruair")
me.password = "strong password"
me.point = 42

print(me.vars())
"""
{
  'id': 1,
  'point': 42,
  'name': 'Edward',
  'nickname': 'haruair',
  'created_at': '2016-01-01T00:00:00.123456',
  'display_name': 'haruair (Edward)'
}
"""

print(me.vars(includes=["password"], excludes=["display_name", "name", "created_at"]))
# {'nickname': 'haruair', 'password': 'strong password', 'point': 100}

print(me.vars(includes_only=["display_name"]))
# {'display_name': 'haruair (Edward)'}

Complex Model

Relationship between models,

from sqlalchemy import ForeignKey
from sqlalchemy.orm import relationship, backref

class Address(Base, Normalizable):
    __tablename__ = 'addresses'
    id = Column(Integer, primary_key=True)
    email = Column(String, nullable=False)

    user_id = Column(Integer, ForeignKey('users.id'))
    user = relationship("User", backref=backref('addresses', order_by=id))

    def __init__(self, email):
        self.email = email

from models import User, Addresses
from yourapp.database import session

me = User("Edward", "haruair")

me.addresses = [
    Address("[e-mail]"),
    Address("[e-mail]")
]

session.add(me)
session.commit()

print(me.vars(includes=["addresses"]))
"""
{
  'id': 1,
  'addresses': [
    {'email': '[e-mail]', 'id': 1, 'user_id': 1},
    {'email': '[e-mail]', 'id': 2, 'user_id': 1}
  ],
  'display_name': 'haruair (Edward)',
  'point': None,
  'nickname': 'haruair',
  'created_at': '2016-09-16T14:16:37.359005',
  'name': 'Edward'
}
"""

Dot Notation

Simple dot notation support. Not much fancy but it’s worth than nothing.

norm1 = me.vars(
    includes=['primary_address'],
    excludes=[
        'primary_address.suburb',
        'primary_address.state'
    ]
)

norm2 = me.vars(
    includes_only=[
        'id',
        'primary_address',
        'primary_address.phone'
    ]
)

If you need more examples, please check test cases in tests directory.