[Python-Dev] New miniconf module

[Phillip J. Eby]

At 07:47 PM 7/26/2006 +0100, David Hopwood wrote:
>Sylvain Fourmanoit wrote:
> > I wrote a data persistence module called miniconf, aimed at making
> > easy to create and safely retrieve configuration info from external,
> > human-readable sources using Python syntax. I feel it would eventually
> > make a nice addition to the standard library.
>
> >From a security point of view, this is a great improvement on the existing
>pickle, marshal, and shelve modules. Those modules could not be safely
>imported from restricted code.
>
>miniconf, OTOH, appears to have an interface compatible with capability
>security. (I have not checked that the compiler.ast module used in its
>implementation is safe.) However:
>
>+Limitations
>+===========
>+
>+miniconf has a few limitations one should be aware of:
>[...]
>+- It is not preemptiple: concurrent calls to dump() or load() will
>+  have unpredictable results and must be avoided.
>
>This limitation should be fixed before the module is added to the standard
>library, IMHO.

It looks like it's trivial to fix; the code uses a strange and unnecessary 
complication of creating nested classes and nested singleton instances 
thereof.  Getting rid of the singletons to create a new instance for each 
dump/load call would suffice to make the implementation re-entrant, 
although de-nesting the classes would also be a good idea.  :)

The loading code could also be made a lot faster by using a dictionary 
mapping AST node types to functions, instead of doing string manipulation 
for each node.  Each function could take 'pedantic' as a parameter, which 
would eliminate the need to have an object at all, let alone a singleton.

Finally, there is an interesting characteristic of the code's 
interpretation of names: any name other than 'True' is interpreted as 'False'!

On the whole, though, I don't see a lot of difference between this format 
and say, JavaScript Object Notation (JSON), which can be parsed and 
generated by many other languages as well as multiple Python libraries already.