[Python-Dev] Enable access to the AST for Python code (original) (raw)

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"."totalprice"), 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.

-- Greg

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