On Sun, Oct 08, 2006 at 12:36:32PM +0530, Noufal Ibrahim wrote:
> Greetings everyone,
> I'm working on a little project that's similar to tcltutor for python.
> I have a string which has some python code. I "compile" and "eval" this
> to get the output. So far so good. However, when this happens, the
> evaluation is happening in the current namespace so I'm afraid of
> symbols being redefined and messed up.
> What I want to do is to create a separate namespace for all the code so
> that I can execute it without worrying about symbol mangling.
>
> Something like if the code I have is
> code = """
> x=5
> if x==5:
> print "Yes"
> else:
> print "No"
> """
>
> I'd like to be able to create a separate module called (say) "tester"
> with contents
>
> def __start_exec__():
> <contents of the code variable>
>
> then say something like
> import tester
> tester.__start_exec__()
>
> to actually run the code. This way, the namespace would be separate.
>
Two points:
1. (Stating something obvious) Code in a module, when called, does
run in a separate namespace. For example, if I run:
import modB
modB.f()
then any variables set in modB are local to modB.
2. If that separation of namespaces is not "strong" enough for you,
try something like the following:
exec somecode in globalDict
where globalDict is a dictionary. globalDict will be the
namespace used by somecode, and, for example, variables created
(perhaps using assignment) in somecode will be created in
globalDict rather than in the current namespace. See:
http://docs.python.org/ref/exec.html.
Dave
--
Dave Kuhlman
http://www.rexx.com/~dkuhlman
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