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Django-Estimators
=================
Tidy Persistence and Retrieval for Machine Learning
Intro
-----
Django-Estimators helps persist and track machine learning models (aka estimators) and datasets.
This library provides a series of proxy objects that wrap common python machine learning objects and dataset objects. As a result, this library can be used to version, track progress and deploy models. It's highly extensible and can be used with almost any python object (scikit-learn, numpy arrays, modules, methods).
This repo utilizes django as an ORM. If you'd like to work outside of django, try the sqlalchemy-based `estimators <https://github.com/fridiculous/estimators.git>`_ library instead.
Installation
------------
Django-estimators is on PyPI, so just run: ::
pip install django-estimators
Quick start
-----------
1. Add "estimators" to your INSTALLED_APPS django setting like this
::
INSTALLED_APPS = [
...
'estimators',
]
2. To create the estimators table, run
::
python manage.py migrate
3. Run ``python manage.py shell`` and get create new models like so
::
from sklearn.ensemble import RandomForestClassifier
rfc = RandomForestClassifier()
from estimators.models import Estimator
est = Estimator(estimator=rfc)
est.description = 'a simple forest'
est.save()
4. Retrieve your model, using the classic django orm, we can pull the last Estimator
::
est = Estimator.objects.last()
# now use your estimator
est.estimator.predict(X)
Use Case: Retrieving Models/Estimators
--------------------------------------
If you aren't sure if it exists, the recommended method is to use the `get_or_create` method
::
est = Estimator.objects.get_or_create(estimator=object)
# or potentially update it with update_or_create
est = Estimator.objects.update_or_create(estimator=object)
If you already have the model, in this case of type object
::
est = Estimator.objects.filter(estimator=object).first()
If you know the unique hash of the model
::
est = Estimator.objects.filter(object_hash='d9c9f286391652b89978a6961b52b674').first()
Use Case: Persisting and Retrieving DataSets
--------------------------------------------
The `DataSet` class functions just like the `Estimator` class. If you have
a numpy matrix or a pandas dataframe, you can wrap it with a DataSet object
::
import numpy as np
import pandas as pd
df = pd.DataFrame(np.random.randint(0,10,(100,8)))
from estimators.models import DataSet
ds = DataSet(data=df)
ds.save()
You can pull that same DataSet object later with
::
ds = DataSet.objects.latest('create_date')
And if you already have the dataset
::
ds = DataSet.objects.filter(data=df).first()
Use Case: Persisting Predictions and Results
--------------------------------------------
Sometimes the most valuable part of a machine learning is the whole process.
Using an ``Evaluator`` object, we can define the relationships between X_test, y_test and
y_predicted ahead of time.
Then we can evaluate the evaluation plan, which in turn calls the ``predict`` method on the estimator
and then presists all the wrapped objects.
Here's a demo of using an Evaluator.
::
from sklearn.datasets import load_digits
from sklearn.ensemble import RandomForestClassifier
digits = load_digits() # 1797 by 64
X = digits.data
y = digits.target
# simple splitting for validation testing
X_train, X_test = X[:1200], X[1200:]
y_train, y_test = y[:1200], y[1200:]
rfc = RandomForestClassifier()
rfc.fit(X_train, y_train)
Now create your evaluation plan
::
from estimators.models import Evaluator
plan = Evaluator(X_test=X_test, y_test=y_test, estimator=rfc)
result = plan.evaluate() # executes `predict` method on X_test
And you can view all the atributes on the evaluation result
::
result.estimator
result.X_test
result.y_test # optional, used with supervised classifiers
result.y_predicted
Using with Jupyter Notebook (or without a django app)
-----------------------------------------------------
Django-Estimators can run as a standalone django app.In order to have access to the django db, you'll need to set up the environment variable to load up your django project. In ipython, by default you can set the environment variable ``DJANGO_SETTINGS_MODULE`` to ``estimators.template_settings`` like so
::
import os
import django
os.environ['DJANGO_SETTINGS_MODULE'] = "estimators.template_settings"
django.setup()
If you're creating a new database (by default it's ``db.sqlite3``). Therefore we need to run migrations, so in python
::
from django.core.management import call_command
call_command('migrate')
Now you can continue you as usual... ::
from estimators.models import Estimator
To use your own custom settings, make a copy of the ``estimators.template_settings`` and edit the fields. Like above, run ``os.environ['DJANGO_SETTINGS_MODULE'] = "custom_settings_file"`` before running ``django.setup()``.
Development Installation
------------------------
To install the latest version of django-estimators, clone the repo, change directory to the repo, and pip install it into your current virtual environment.::
$ git clone git@github.com:fridiculous/django-estimators.git
$ cd django-estimators
$ <activate your project’s virtual environment>
(virtualenv) $ pip install -e . # the dot specifies for this current repo