Python __setattr__ and __getattr__ for global scope?
- by KT
Suppose I need to create my own small DSL that would use Python to describe a certain data structure. E.g. I'd like to be able to write something like
f(x) = some_stuff(a,b,c)
and have Python, instead of complaining about undeclared identifiers or attempting to invoke the function some_stuff, convert it to a literal expression for my further convenience.
It is possible to get a reasonable approximation to this by creating a class with properly redefined __getattr__ and __setattr__ methods and use it as follows:
e = Expression()
e.f[e.x] = e.some_stuff(e.a, e.b, e.c)
It would be cool though, if it were possible to get rid of the annoying "e." prefixes and maybe even avoid the use of []. So I was wondering, is it possible to somehow temporarily "redefine" global name lookups and assignments? On a related note, maybe there are good packages for easily achieving such "quoting" functionality for Python expressions?
