[Python-Dev] Enable access to the AST for Python code

Greg greg.ewing at canterbury.ac.nz
Fri May 22 04:06:54 CEST 2015

On 22/05/2015 1:33 p.m., Ethan Furman wrote:
> Going back to the OP:
>>     select(c for c in Customer if sum(c.orders.price) > 1000)
>> which compile into and run SQL like this:
>>     SELECT "c"."id"
>>     FROM "Customer" "c"
>>     LEFT JOIN "Order" "order-1" ON "c"."id" = "order-1"."customer"
>>     GROUP BY "c"."id"
>>     HAVING coalesce(SUM("order-1"."total_price"), 0) > 1000
> That last code is /not/ Python.  ;)

More importantly, it's not Python *semantics*. You can't view
it as simply a translation of the Python expression into a
different language.

I still think this is really a macro facility by a different
name. I'm not saying that's a bad thing, just pointing it out.

The main difference is that a macro would (or at least could)
be expanded at compile time, whereas this would require
processing the AST each time it's used.


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