Re: [Python-Dev] Nested scopes resolution -- you can breathe again!

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"GvR" == Guido van Rossum writes:

GvR> The Python equivalent of this is a magical import that is GvR> recognized by the compiler; this was also proposed by David GvR> Scherer for making integer division yield a float. (See GvR> http://mail.python.org/pipermail/edu-sig/2000-May/000499.html) GvR> You could say that Perl's "use" statement is similar. GvR> We haven't decided yet which magical import; two proposals are: GvR> import __nested_scopes__ from __future__ import GvR> nested_scopes GvR> The magical import only affects the source file in which it GvR> occurs. It is recognized by the compiler as it is scanning the GvR> source code. It must appear at the top-level (no "if" or "try" GvR> or "def" or anything else around it) and before any code that GvR> could be affected. We'll need to write a short PEP describing this approach and offering some guidance about how frequently we intend to use it. I think few of us would be interested in making frequent use of it to add all sorts of variant language features. Rather, I imagine it would be used only -- or primarily -- to introduce new features that will become standard at some point. GvR> We also believe that the magical import mechanism is useful GvR> enough to be reused for other situations like this; Tim will GvR> draft a PEP to describe in excruciating detail. I'm happy to hear that Tim will draft this PEP. He didn't mention it at lunch today or I would have given him a big hug (or bought him a Coke). As Tim knows, I think the PEP needs to say something about whether these magic imports create name bindings and what objects are bound to the names. Will we need an __nested_scopes__.py in the Lib directory? Jeremy