Keeping track of changes - Django
Quoth my elementary chemistry teacher: "If you don't write it down, it didn't happen", therefore save logs in a file.
Since the log information is disjoint from your application data (it's meta-data, actually), keep them separate. You could log to a database table but it should be distinct from your model.
Text pickle data is difficult for humans to read, binary pickle data even more so; log in an easily parsed format and the data can be imported into analysis software easily.
I have various models of which I would like to keep track and collect statistical data.
The problem is how to store the changes throughout time.
I thought of various alternative:

Storing a log in a TextField, open it and update it every time the model is saved.
Alternatively pickle a list and store it in a TextField.
Save logs on hard drive.


What are your suggestions?