[Python-Dev] Pickling Question

Patrick K. O'Brien pobrien@orbtech.com
Sat, 9 Nov 2002 07:54:33 -0600

In my pickling article [1] I looked at various ways to handle schema 
evolution issues. When it came to module name and location changes, I 
wrote the following:

"A module name or location change is conceptually similar to a class 
name change but must be handled quite differently. That's because the 
module information is stored in the pickle but is not an attribute that 
can be modified through the standard pickle interface. In fact, the 
only way to change the module information is to perform a search and 
replace operation on the actual pickle file itself. Exactly how you 
would do this depends on your operating system and the tools you have 
at your disposal. And obviously this is a situation where you will want 
to back up your files in case you make a mistake. But the change should 
be fairly straightforward and will work equally well with the binary 
pickle format as with the text pickle format."

I don't feel that this solution is entirely satisfactory and so I 
thought I would ask (a bit late, I know) whether I am completely 
correct in my assertions. If not, how else can this be handled. If so, 
is there any chance of adding a better way to handle this situation?

[1] http://www-106.ibm.com/developerworks/library/l-pypers.html

Patrick K. O'Brien
Orbtech      http://www.orbtech.com/web/pobrien
"Your source for Python programming expertise."