Aug. 26, 2011
7:14 a.m.
2011/8/26 Greg Ewing <greg.ewing@canterbury.ac.nz>
The most popular (as from what I can see) thing right now where people
start seeing that += is slow is when they try to do that on PyPy (which doesn't have hack like CPython, who is still slow) and ask "why my pypy code is sooooo slow".
To me that suggests it may have been a mistake to try to optimise += at all in CPython, as it gives people misleading expectations.
The author of this optimization is also the lead designer of PyPy... -- Amaury Forgeot d'Arc