Re: modifying locals

[Steve Holden]

John [H2O] wrote:

I would like to write a function to write variables to a file and modify a
few 'counters'. This is to replace multiple instances of identical code in a
module I am writing.
>
This is my approach:
>
def write_vars(D):
""" pass D=locals() to this function... """
for key in D.keys():
exec("%s = %s" % (key,D[key]))
>

Note that this code will likely fail to execute if D[key] is some object
whose str() method does not return a valid Python expression.

outfile.write(. ..)
numcount += 1
do this, do that...
>
the issue is that at the end, I want to return outfile, numcount, etc... but
I would prefer to not return them explicitly, that is, I would just like
that the modified values are reflected in the script. How do I do this?
Using global? But that seems a bit dangerous since I am using exec.
>

Return them as a tuple, using an unpacking assignment to bind the
different elements to different names.

Bringing up another matter... is there a better way to do this that doesn't
use exec?
>

It's not really obvious why you are trying to replicate the caller's
namespace inside this function. Perhaps you could explain a little more
what you are trying to achieve.

regards
Steve
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