\begin{itemize}
\item The inner loops for \class{list} and \class{tuple} slicing
- were optimized and now run about one-third faster.
+ were optimized and now run about one-third faster. The inner
+ loops were also optimized for \class{dict} with performance
+ boosts to \method{keys()}, \method{values()}, \method{items()},
+\method{\iterkeys()}, \method{\itervalues()}, and \method{iteritems()}.
\item The machinery for growing and shrinking lists was optimized
for speed and for space efficiency. Small lists (under eight elements)
Core and builtins
-----------------
+- Optimized dict iterators, creating separate types for each
+ and having them reveal their length. Also optimized the
+ methods: keys(), values(), and items().
+
- Implemented a newcode opcode, LIST_APPEND, that simplifies
the generated bytecode for list comprehensions and further
improves their performance (about 35%).