Op 2005-11-28, Peter Hansen schreef <[EMAIL PROTECTED]>: > Mike Meyer wrote: >> It seems that the distinction between tuples and lists has slowly been >> fading away. What we call "tuple unpacking" works fine with lists on >> either side of the assignment, and iterators on the values side. IIRC, >> "apply" used to require that the second argument be a tuple; it now >> accepts sequences, and has been depreciated in favor of *args, which >> accepts not only sequences but iterators. >> >> Is there any place in the language that still requires tuples instead >> of sequences, except for use as dictionary keys? > > Would it be possible to optimize your "frozenlist" so that the objects > would be created during compilation time and rather than only during > runtime? If not then tuples() have a distinct performance advantage in > code like the following where they are used as local constants: > > >>> def func(x): > ... if x in (1, 3, 5, 7, 8): > ... print 'x is really odd' > ... > >>> import dis > >>> dis.dis(func) > .... > 3 20 LOAD_FAST 0 (x) > 23 LOAD_CONST 8 ((1, 3, 5, 7, 8)) > 26 COMPARE_OP 6 (in) > > >>> def func(x): > ... if x in [1,3,5,7,8]: > ... print 'x is really odd' > ... > >>> dis.dis(func) > ... > 3 20 LOAD_FAST 0 (x) > 23 LOAD_CONST 2 (1) > 26 LOAD_CONST 3 (3) > 29 LOAD_CONST 4 (5) > 32 LOAD_CONST 5 (7) > 35 LOAD_CONST 6 (8) > 38 BUILD_LIST 5 > 41 COMPARE_OP 6 (in)
I'm probably missing something, but what would be the problem if this list was created during compile time? -- Antoon Pardon -- http://mail.python.org/mailman/listinfo/python-list
