function local namespace question
Diez B. Roggisch
deets at nospam.web.de
Thu Jul 9 08:54:25 EDT 2009
Dave Angel wrote:
> Paul LaFollette wrote:
>> Kind people,
>>
>> Using Python 3.1 under FreeBSD and WinXP.
>>
>> I've been tearing my hair out trying to solve this myself, but I need
>> to ask for help. I want (for obscure reasons) to be able to log
>> transactions in the namespace(s) of a script. Specifically I would
>> like to log creation of identifiers, changes in the binding of
>> identifiers ("assignment") and lookups. This turns out to be pretty
>> easy in the global and local namespaces... I simply subclass dict,
>> override the appropriate operations to include the logging operations
>> I want, and then exec the code using my dictionaries as the global and
>> local namespaces. All of this works just dandy until I try to
>> extend it to functions.
>>
>> I cannot figure out any way to get a hook into the local namespace of
>> a user defined function. I have tried making a wrapper class that
>> grabs the function call and then uses exec to invoke
>> myfunction.__code__ with my own dictionaries. This runs the (no
>> argument) function properly (losing the return value, but I can deal
>> with that) but never accesses the local logging dictionary that I
>> specify in the exec() call. Perhaps the local namespace of a function
>> is not a dict at all?
>>
>> Anyway, is there any way (however clumsy) to do what I want to do?
You might consider using the trace-functionality of python, exposed throug
sys.settrace
It's very expensive of course to do that.
Diez
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