Usage
-----

.. code-block:: python

   from dpath import new as dnew
   mydict = Dict()

   dnew(mydict, "/a/b/c",  15)

   for _ in mydict.get_changed_history():
       print(_)

The output:

::

   /a/b/c

Use clear_changed_history to clear all changed history.

.. code-block:: python

   mydict.clear_changed_history()
   for _ in mydict.get_changed_history():
       print(_)

outputs empty.

Key Points
----------

1. Only tracks changes in values. Field additions and deletions are not being tracked.
2. Every field keeps a ``__tracker`` variable to keep track of all its members that have changed.
3. Always use dnew for updating value of existing path or input new value for tracking to work properly.
   
TODO
----

1. History not valid after
pickle.load
2. building dict from another dict
following expression won't work

.. code-block:: python

   cjs_cfg = Dict(x, track_changes=True)

instead use

.. code-block:: python

   cjs_cfg = Dict(track_changes = True)
   with open("cjs_cfg.pickle", "rb") as fh:
       x = pickle.load(fh)
   for _ in oj.dictWalker(x):
       oj.dnew(cjs_cfg, _[0], _[1])