Things we think the Python community will like.

• Frame optimizations: once a function is called it retains the allocated frame for use in future calls, avoiding allocation and initialization overhead. Frame size has also been slightly reduced.

  PyStone is over 10% higher on RichardJones' test machine, compared to Python 2.4 (from 20242 to 22935). PyBench reports an overall slowdown, attributed to a 150% slowdown in a piece of code that wasn't changed. Sigh.

• Made Gzip readline 30-40% faster (BobIppolito)

• Speed up Unicode operations (AndrewDalke, FredrikLundh). Most notable, repeat is much faster, and most search operations (find, index, count, in) are a LOT faster (20x for the related stringbench tests). Also, rsplit is now as fast as split, and splitlines is nearly as fast as a plain split("\n"). Current stringbench results:

        str(ms) uni(ms) %       comment
        -----------------------------------------------------
        2271.31 3608.32 62.9    TOTAL 2.5a2
        2261.85 1187.84 190.4   TOTAL tuesday
        2230.05 1027.68 217.0   TOTAL wednesday

• (yes, the Unicode string type is now more than twice as fast on this set of tests.)

• Patch 1335972 was a combination bugfix+speedup for string->int conversion. These are the speedups measured on my Windows box for decimal strings of various lengths. Note that the difference between 9 and 10 is the difference between short and long Python ints on a 32-bit box. The patch doesn't actually do anything to speed conversion to long directly; the speedup in those cases is solely due to detecting "unsigned long" overflow more quickly:

        length speedup
        ------ -------
         1       12.4%
         2       15.7%
         3       20.6%
         4       28.1%
         5       33.2%
         6       37.5%
         7       41.9%
         8       46.3%
         9       51.2%
        10       19.5%
        11       19.9%
        12       23.9%
        13       23.7%
        14       23.3%
        15       24.9%
        16       25.3%
        17       28.3%
        18       27.9%
        19       35.7%

• The struct module has been rewritten to pre-compile struct descriptors (similar to the RE module). This gives a 20% speedup, on average, for the test suite [BobIppolito].