README.rst

object-tracker

A pure python object state tracker. Monitor all changes in your object's lifecycle, query the history changelog, and trigger callback functions to capture them.

View the Github repository and the official docs.

$ pip install object-tracker

Tested for python 3.6, 3.7 and above.

Key Features

• Determine if a python object has changed state during it's lifecycle.
• Investigate change history by querying a structured changelog.
• Trigger callback functions whenever an (or any) attribute has changed.
• Use it as a decorator, a class mixin or on its own.

License

Copyright (c) Saurabh Pujari
All rights reserved.

This source code is licensed under the BSD-style license found in the LICENSE file in the root directory of this source tree.

Usage :

Use the @track decorator to track an object's attributes.

from object_tracker import track

def observer(attr, old, new):
    print(f"Observer : {attr} -> {old} - {new}")

@track('name', 'age', observers=[observer,])
class User:
    def __init__(self, name, age):
        self.name = name
        self.age = age

user = User(name='Alice', age=30)
user.name = 'Bob'
# Observer : name -> Alice - Bob
print(user.tracker.has_changed())
# True
print(user.tracker.has_attribute_changed('name'))
# True

Or use the Tracker class

class MyClass:
    pass

obj = MyClass()
tracker = Tracker(obj)
obj.attribute = 'new_value'
print(tracker.has_changed(obj))
# True

Or use it with the mixin class TrackerMixin:

from object_tracker import TrackerMixin, Tracker

 class User(TrackerMixin):
     def __init__(self, name, age):
         self.name = name
         self.age = age
         self.tracker = Tracker()