Skip to main content

Custom field type for storing and retrieving bit-packed flags as enums.

Project description

# BitField for [motorengine](https://github.com/heynemann/motorengine)
Custom field type for storing and retrieving bit-packed flags as enums.

Inspiration from [`enum.IntFlag` documentation](https://docs.python.org/3.6/library/enum.html#intflag).

## Installation
`motorengine-bitfield` requires a minimum Python version of 3.6.2.

Add the code directly to your project or install from pip with:
```shell
pip install motorengine-bitfield
```

## Examples
```python
from bitfield import BitField

# create an enum to use in our example
class UserFlags(enum.IntFlag):
IS_ACTIVE = enum.auto() # least-significant bit
IS_ADMIN = enum.auto()
HAS_LOGGED_IN = enum.auto()
HAS_SEEN_INTRO = enum.auto()
SUBSCRIBED_TO_NEWSLETTER = enum.auto() # most-significant bit

# use the enum in our Document mapping
class User(motorengine.Document):
name = StringField()
email = StringField()
flags = BitField(UserFlags)

# let's test one out!
user = User(
name='Bit Field',
email='example@bitfield.py',
flags=(UserFlags.IS_ACTIVE | UserFlags.SUBSCRIBED_TO_NEWSLETTER),
)

# enum instances are serialized into an integer
user.to_son()
# {'name': 'Bit Field', 'email': 'example@bitfield.py', 'flags': 17}
user = loop.run_until_complete(
user.save()
)

# and deserialized into the original enum
retrieved_user = loop.run_until_complete(
User.objects.get(user._id)
)
retrieved_user.flags
# <UserFlags.SUBSCRIBED_TO_NEWSLETTER|IS_ACTIVE: 17>
bool(user.flags & UserFlags.IS_ADMIN)
# False

# a BitField value also be created with plain integers
int_user = loop.run_until_complete(
User.objects.create(flags=(2**5 - 1))
)
loop.run_until_complete(User.objects.get(int_user._id)).flags
# <UserFlags.SUBSCRIBED_TO_NEWSLETTER|HAS_SEEN_INTRO|HAS_LOGGED_IN|IS_ADMIN|IS_ACTIVE: 31>

# or from strings of binary
str_user = loop.run_until_complete(
User.objects.create(flags='01101'))
)
loop.run_until_complete(User.objects.get(str_user._id)).flags
# <UserFlags.HAS_SEEN_INTRO|HAS_LOGGED_IN|IS_ACTIVE: 13>
```

## Development
Tests are written with pytest and can be run with `python setup.py test`.

Pull requests always welcome!


Project details


Release history Release notifications

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
motorengine_bitfield-1.0.0-py3-none-any.whl (5.6 kB) Copy SHA256 hash SHA256 Wheel py3 Jun 23, 2017
motorengine-bitfield-1.0.0.tar.gz (16.8 kB) Copy SHA256 hash SHA256 Source None Jun 23, 2017

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page