En Fri, 09 Mar 2007 23:45:50 -0300, Steven D'Aprano <[EMAIL PROTECTED]> escribió:
> On Fri, 09 Mar 2007 18:57:42 -0300, Gabriel Genellina wrote: > >> En Fri, 09 Mar 2007 17:15:44 -0300, Paulo da Silva >> <[EMAIL PROTECTED]> escribió: >> >>> What is the best way to have something like the bisect_left >>> method on a list of lists being the comparision based on an >>> specified arbitrary i_th element of each list element? >>> >>> Is there, for lists, something equivalent to the __cmp__ function for >>> classes? >> >> lists *are* classes (at least since Python 2.2) > > Not quite. Classes and types are *almost* the same, but not exactly. I were talking about new style classes, that's why I said Python 2.2 >>>> type(list) > <type 'type'> >>>> class Spam: > ... pass > ... >>>> type(Spam) > <type 'classobj'> py> class New(object): pass ... py> type(New) <type 'type'> New-style clases are instances of type too (like list, tuple and other builtins), and subclasses of object: py> New.mro() [<class '__main__.New'>, <type 'object'>] py> list.mro() [<type 'list'>, <type 'object'>] > Usually the difference doesn't make a difference, but sometimes it does. > >>>> Spam.x = 3 >>>> list.x = 3 > Traceback (most recent call last): > File "<stdin>", line 1, in ? > TypeError: can't set attributes of built-in/extension type 'list' That's not because list is a builtin type, but because it lacks (by design) any means to store instance attributes (it has an empty tp_dictoffset slot, by example). Functions, exceptions, modules are examples of builtin types whose instances can handle attributes. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
