exec in a nested function yields an error

Scott David Daniels Scott.Daniels at Acm.Org
Tue Jan 13 19:13:47 CET 2009


TP wrote:
> ...
 > def f():
>     def f_nested():
>         exec "a=2"
>         print a
> f()
> ... What is the problem? Why?

What it wants is you to provide the "in context" portion of the
exec statement.  I expect the reason it fails is that there is no
dictionary that is available as locals that encompasses the locals
of both f and f_nested, so you'll have to be explicit about what
you mean.

So, the code wants you to say something like:
     def f():
         def f_nested():
             exec "a=2" in globals(), locals()
             print a
         return f_nested
     f()

--Scott David Daniels
Scott.Daniels at Acm.Org



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