grocery_stocker wrote: > Okay, I was thinking more about this. I think this is also what is > irking me. Say I have the following.. > >>>> a = [1,2,3,4] >>>> for x in a: > ... print x > ... > 1 > 2 > 3 > 4 >>>> > > Would 'a' somehow call __iter__ and next()? If so, does python just > perform this magically?
yes! in fact you can see them: Python 2.5.4 (r254:67916, Mar 23 2009, 17:43:35) [GCC 4.3.2 [gcc-4_3-branch revision 141291]] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> l = [1,2,3,4] >>> dir(l) ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__delslice__', '__doc__', '__eq__', '__ge__', '__getattribute__', '__getitem__', '__getslice__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__', 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort'] >>> l.__iter__ <method-wrapper '__iter__' of list object at 0x7f5e61618c68> >>> i = l.__iter__() >>> dir(i) ['__class__', '__delattr__', '__doc__', '__getattribute__', '__hash__', '__init__', '__iter__', '__length_hint__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__str__', 'next'] >>> i.next() 1 >>> i.next() 2 note that the list only has __iter__, not next. calling __iter__() returns an iterator (something that has a next method) and calling next on that gives you the same result. dir() just shows all the attributes of an object. andrew -- http://mail.python.org/mailman/listinfo/python-list
