文档介绍：Python 3000(PyCon, 24-Feb-02007)Guido van ******@******@24 Feb 02007(c) 2007 Python Software Foundation2What Is Python 3000???The next major Python release–To be released as Python ?The first one in a long time to be patible–But pletely different or unusual?Concept first formed around 2000–Py3k nickname was a play on Windows 2000?Goal: to correct my early design mistakes–Those that would require patibility to fix–Reduce cognitive load for first-time learners?Work and thinking started for real last year24 Feb 02007(c) 2007 Python Software Foundation3Activity Since Last Year?Lots of design discussions–(too many, if you ask me :-)?Some PEPs were written–(but not enough…)?Lots of code was written–(just the right amount!)–(but we're not done yet!!)24 Feb 02007(c) 2007 Python Software Foundation4Python Timeline?PEPs to pleted: April 2007??: June 2007? final: June 2008?parison, the timeline:?: December 2007? final: April 2008There will also be a timeline24 Feb 02007(c) 2007 Python Software Foundation5Rest of the Talk?Highlight some of the most visible changes–print function, dict views, comparisons, unicode, …?How to convert to code?Notational convention:*= pletely implemented**= not yet implemented24 Feb 02007(c) 2007 Python Software Foundation6No More Classic Classes?In … :–class C:# classic class ( … )–class C(object):# new-style class (old now :-)?In :–both are new-style classes (just say "classes")?Differences are subtle, few of you will notice24 Feb 02007(c) 2007 Python Software Foundation7Print is a Function?print x, y-> print(x, y)?print x,-> print(x, end=" ")?print >>f, x-> print(x, file=f)?Automatic translation is 98% correct?Fails for cases involving softspace cleverness:–print "x\n", "y" doesn 't insert a space before y–print("x\n", "y") does–ditto for print "x\t", "y"24 Feb 02007(c) 2007 Python Software Foundation8Dictionary Views?Inspired by Java Collections Framework?Remove .iterkeys(), .iteritems(),