Track changes to lists and dictionaries in python?

Question

I have a class where the instances of this class needs to track the changes to its attributes.

Example: obj.att = 2 would be something that\'s easily tr

Answer 1

You can also wrap the dictionary or list methods you want to track and make sure you do what you want inside the wrapper. Here is a dict example:

from functools import wraps

def _setChanged(func):
    @wraps(func)
    def wrappedFunc(self, *args, **kwargs):
        self.changed = True
        return func(self, *args, **kwargs)
    return wrappedFunc

def _trackObjectMethods(calssToTrack):
    for methodName in dir(calssToTrack):
        if methodName in calssToTrack._destructive:
            setattr(calssToTrack, methodName, _setChanged(getattr(calssToTrack, methodName)))

class Dictionary(dict):
    _destructive = ('__delitem__', '__setitem__', 'clear', 'pop', 'popitem', 'setdefault', 'update')

    def __init__(self, *args, **kwargs):
        self.changed = False
        super().__init__(*args, **kwargs)

_trackObjectMethods(Dictionary)

d = Dictionary()
print(d.changed)
d["1"] = 'test'
print(d.changed)
d.changed = False
print(d.changed)
d["12"] = 'test2'
print(d.changed)

As you can see if any items of the dictionary changes, the custom variable that I added to my custom Dictionary object will be set to True. This way I can tell if the object has changes since the last time I had set the changed variable to False.