[Tutor] Named-value formatting fails

[Tim Johnson]

I'm using 2.6.5 on ubuntu 10.04.
I'm evaluating a very large string using a named-value formatting
scheme. The process fails with the following error message:
"""not enough arguments for format string"""
In the first place, I wouldn't expect to even see this error
message, because as the python documentation says:
"""
Python calls the get-item method of the right-hand-side mapping
(__getitem__), when the righthand side is an instance object.
"""
As for the right-hand mapping - I'm using the following:
class Evalx:
    def __init__(self, localvals = None, globalvals = None):
        if localvals is None: 
            self.locals = sys._getframe(1).f_locals
        else : 
            self.locals = locals
        if globalvals is None: 
            self.globals = sys._getframe(1).f_globals
        else : 
            self.globals = globals
    def __getitem__(self,key):
        return eval(key,self.globals,self.locals)
the implementation looks like this:
self.content = content % Evalx()

I would really appreciate some insights on this issue.
I don't really know how to debug this, except for to look for some
"%s" in the `content' string.
TIA
-- 
Tim 
tim at johnsons-web.com or akwebsoft.com
http://www.akwebsoft.com