[Python-Dev] Change to yield-from implementation (original) (raw)

Greg Ewing greg.ewing at canterbury.ac.nz
Mon Apr 9 14:24:07 CEST 2012


Mark Shannon wrote:

We have recently removed the fyieldfrom field from the frame object. (http://bugs.python.org/issue14230)

Hey, wait a minute. Did anyone consider the performance effect of that change on deeply nested yield-froms?

The way it was, a yield-from chain was traversed by a very tight C loop that found the end frame and resumed it directly. If I understand what you've done correctly, now it has to enter and execute a bytecode in every frame along the way.

-- Greg



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