Iterators phase 1. This comprises: new slot tp_iter in type object, plus new flag Py_TPFLAGS_HAVE_ITER new C API PyObject_GetIter(), calls tp_iter new builtin iter(), with two forms: iter(obj), and iter(function, sentinel) new internal object types iterobject and calliterobject new exception StopIteration new opcodes for "for" loops, GET_ITER and FOR_ITER (also supported by dis.py) new magic number for .pyc files new special method for instances: __iter__() returns an iterator iteration over dictionaries: "for x in dict" iterates over the keys iteration over files: "for x in file" iterates over lines TODO: documentation test suite decide whether to use a different way to spell iter(function, sentinal) decide whether "for key in dict" is a good idea use iterators in map/filter/reduce, min/max, and elsewhere (in/not in?) speed tuning (make next() a slot tp_next???)

--- a/Python/import.c	Fri Apr 20 19:04:55 2001 +0000
+++ b/Python/import.c	Fri Apr 20 19:13:02 2001 +0000
@@ -43,7 +43,7 @@
 /* XXX Perhaps the magic number should be frozen and a version field
    added to the .pyc file header? */
 /* New way to come up with the magic number: (YEAR-1995), MONTH, DAY */
-#define MAGIC (60202 | ((long)'\r'<<16) | ((long)'\n'<<24))
+#define MAGIC (60420 | ((long)'\r'<<16) | ((long)'\n'<<24))
 
 /* Magic word as global; note that _PyImport_Init() can change the
    value of this global to accommodate for alterations of how the