[Python-Dev] speeding up list append calls

"Martin v. Löwis" martin at v.loewis.de
Wed Sep 14 18:55:12 CEST 2005

Neal Norwitz wrote:
> This code doesn't really work in general.  It assumes that any append
> function call is a list method, which is obviously invalid.  But if a
> variable is known to be a list (ie, local and assigned as list
> (BUILD_LIST) or a list comprehension), could we do something like this
> as a peephole optimization?

Alternatively, couldn't LIST_APPEND check that this really is a list,
and, if it isn't, fall back to PyObject_CallMethod?

Not sure which .append call is performed most frequently, but the
traditional trick of caching x.append in a local variable might give
you most of the speedup.


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