Gregory Piñero <[EMAIL PROTECTED]> wrote:
> I'm curious why this code isn't working how I expect it to:
>
> import sys
> d=3
>
> def func1(a,b,c):
> print a,b,c,d
> print sys.path
>
> exec "func1(1,2,3)" in {'func1':func1}
>
> ----
> returns:
> 1 2 3 3
> [ sys.path stuff ....]
>
> Since I'm telling exec to operate only within the context of the
> dictionary I give it, why does it still see sys.path and d? I figured
> it would throw a NameError.
>
> Is there a way to call exec such that it won't have access to any more
> objects than I explicitly give it?
func1 accesses its globals through func1.func_globals (which you can't
reassign -- it's a read-only attribute).
You may make a new function object w/ a different globals dict...:
>>> g = type(func1)(func1.func_code, {})
and that will fail (even when called directly, but similarly if exec'd)
as it's missing key 'd' in its globals:
>>> g(1, 2, 3)
1 2 3
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 2, in func1
NameError: global name 'd' is not defined
The globals dict you pass to exec is the globals at the time of CALL,
not the globals seen from INSIDE func1; that's always going to be the
func_globals attribute of the function object, so you need to control
that (by suitably building a new function object as you require).
Alex
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