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- New builtin function enumerate(x), from PEP 279. Example:
 enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c"). The argument can be an arbitrary iterable object.
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‎Include/Python.h‎

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@@ -91,6 +91,7 @@
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#include "tupleobject.h"
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#include "listobject.h"
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#include "dictobject.h"
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#include "enumobject.h"
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#include "methodobject.h"
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#include "moduleobject.h"
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#include "funcobject.h"

‎Include/enumobject.h‎

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#ifndef Py_ENUMOBJECT_H
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#define Py_ENUMOBJECT_H
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/* Enumerate Object */
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#ifdef __cplusplus
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extern "C" {
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#endif
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extern DL_IMPORT(PyTypeObject) PyEnum_Type;
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#ifdef __cplusplus
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}
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#endif
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#endif /* !Py_ENUMOBJECT_H */

‎Lib/test/test_enumerate.py‎

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from __future__ import generators
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import unittest
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import test_support
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seq, res = 'abc', [(0,'a'), (1,'b'), (2,'c')]
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class G:
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'Sequence using __getitem__'
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def __init__(self, seqn):
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self.seqn = seqn
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def __getitem__(self, i):
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return self.seqn[i]
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class I:
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'Sequence using iterator protocol'
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def __init__(self, seqn):
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self.seqn = seqn
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self.i = 0
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def __iter__(self):
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return self
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def next(self):
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if self.i >= len(self.seqn): raise StopIteration
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v = self.seqn[self.i]
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self.i += 1
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return v
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class Ig:
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'Sequence using iterator protocol defined with a generator'
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def __init__(self, seqn):
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self.seqn = seqn
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self.i = 0
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def __iter__(self):
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for val in self.seqn:
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yield val
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class X:
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'Missing __getitem__ and __iter__'
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def __init__(self, seqn):
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self.seqn = seqn
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self.i = 0
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def next(self):
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if self.i >= len(self.seqn): raise StopIteration
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v = self.seqn[self.i]
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self.i += 1
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return v
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class E:
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'Test propagation of exceptions'
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def __init__(self, seqn):
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self.seqn = seqn
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self.i = 0
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def __iter__(self):
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return self
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def next(self):
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3/0
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class N:
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'Iterator missing next()'
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def __init__(self, seqn):
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self.seqn = seqn
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self.i = 0
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def __iter__(self):
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return self
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class EnumerateTestCase(unittest.TestCase):
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enum = enumerate
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def test_basicfunction(self):
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self.assertEqual(type(self.enum(seq)), self.enum)
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e = self.enum(seq)
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self.assertEqual(iter(e), e)
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self.assertEqual(list(self.enum(seq)), res)
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self.enum.__doc__
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def test_getitemseqn(self):
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self.assertEqual(list(self.enum(G(seq))), res)
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e = self.enum(G(''))
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self.assertRaises(StopIteration, e.next)
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def test_iteratorseqn(self):
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self.assertEqual(list(self.enum(I(seq))), res)
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e = self.enum(I(''))
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self.assertRaises(StopIteration, e.next)
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def test_iteratorgenerator(self):
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self.assertEqual(list(self.enum(Ig(seq))), res)
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e = self.enum(Ig(''))
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self.assertRaises(StopIteration, e.next)
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def test_noniterable(self):
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self.assertRaises(TypeError, self.enum, X(seq))
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def test_illformediterable(self):
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self.assertRaises(TypeError, list, self.enum(N(seq)))
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def test_exception_propagation(self):
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self.assertRaises(ZeroDivisionError, list, self.enum(E(seq)))
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class MyEnum(enumerate):
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pass
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class SubclassTestCase(EnumerateTestCase):
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enum = MyEnum
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def suite():
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suite = unittest.TestSuite()
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suite.addTest(unittest.makeSuite(EnumerateTestCase))
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suite.addTest(unittest.makeSuite(SubclassTestCase))
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return suite
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def test_main():
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test_support.run_suite(suite())
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if __name__ == "__main__":
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test_main()

‎Makefile.pre.in‎

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@@ -257,6 +257,7 @@ OBJECT_OBJS= \
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Objects/cobject.o \
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Objects/complexobject.o \
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Objects/descrobject.o \
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Objects/enumobject.o \
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Objects/fileobject.o \
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Objects/floatobject.o \
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Objects/frameobject.o \
@@ -443,6 +444,7 @@ PYTHON_HEADERS= \
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Include/complexobject.h \
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Include/descrobject.h \
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Include/dictobject.h \
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Include/enumobject.h \
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Include/fileobject.h \
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Include/floatobject.h \
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Include/funcobject.h \

‎Misc/NEWS‎

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@@ -6,6 +6,10 @@ Type/class unification and new-style classes
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77
Core and builtins
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- New builtin function enumerate(x), from PEP 279. Example:
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enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c").
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The argument can be an arbitrary iterable object.
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- The assert statement no longer tests __debug__ at runtime. This means
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that assert statements cannot be disabled by assigning a false value
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to __debug__.

‎Objects/enumobject.c‎

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/* enumerate object */
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#include "Python.h"
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typedef struct {
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PyObject_HEAD
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long en_index; /* current index of enumeration */
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PyObject* en_sit; /* secondary iterator of enumeration */
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} enumobject;
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PyTypeObject PyEnum_Type;
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static PyObject *
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enum_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
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{
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enumobject *en;
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PyObject *seq = NULL;
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static char *kwlist[] = {"sequence", 0};
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if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:enumerate", kwlist,
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&seq))
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return NULL;
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en = (enumobject *)type->tp_alloc(type, 0);
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if (en == NULL)
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return NULL;
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en->en_index = 0;
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en->en_sit = PyObject_GetIter(seq);
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if (en->en_sit == NULL) {
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Py_DECREF(en);
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return NULL;
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}
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return (PyObject *)en;
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}
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static void
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enum_dealloc(enumobject *en)
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{
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PyObject_GC_UnTrack(en);
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Py_XDECREF(en->en_sit);
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en->ob_type->tp_free(en);
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}
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static int
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enum_traverse(enumobject *en, visitproc visit, void *arg)
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{
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if (en->en_sit)
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return visit(en->en_sit, arg);
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return 0;
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}
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static PyObject *
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enum_next(enumobject *en)
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{
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PyObject *result;
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PyObject *next_index;
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PyObject *next_item = PyIter_Next(en->en_sit);
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if (next_item == NULL)
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return NULL;
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result = PyTuple_New(2);
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if (result == NULL) {
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Py_DECREF(next_item);
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return NULL;
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}
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next_index = PyInt_FromLong(en->en_index++);
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if (next_index == NULL) {
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Py_DECREF(next_item);
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Py_DECREF(result);
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return NULL;
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}
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PyTuple_SET_ITEM(result, 0, next_index);
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PyTuple_SET_ITEM(result, 1, next_item);
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return result;
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}
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static PyObject *
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enum_getiter(PyObject *en)
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{
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Py_INCREF(en);
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return en;
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}
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static PyMethodDef enum_methods[] = {
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{"next", (PyCFunction)enum_next, METH_NOARGS,
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"return the next (index, value) pair, or raise StopIteration"},
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{NULL, NULL} /* sentinel */
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};
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static char enum_doc[] =
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"enumerate(iterable) -> create an enumerating-iterator";
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PyTypeObject PyEnum_Type = {
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PyObject_HEAD_INIT(&PyType_Type)
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0, /* ob_size */
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"enumerate", /* tp_name */
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sizeof(enumobject), /* tp_basicsize */
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0, /* tp_itemsize */
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/* methods */
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(destructor)enum_dealloc, /* tp_dealloc */
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0, /* tp_print */
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0, /* tp_getattr */
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0, /* tp_setattr */
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0, /* tp_compare */
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0, /* tp_repr */
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0, /* tp_as_number */
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0, /* tp_as_sequence */
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0, /* tp_as_mapping */
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0, /* tp_hash */
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0, /* tp_call */
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0, /* tp_str */
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PyObject_GenericGetAttr, /* tp_getattro */
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0, /* tp_setattro */
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0, /* tp_as_buffer */
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Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
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Py_TPFLAGS_BASETYPE, /* tp_flags */
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enum_doc, /* tp_doc */
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(traverseproc)enum_traverse, /* tp_traverse */
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0, /* tp_clear */
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0, /* tp_richcompare */
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0, /* tp_weaklistoffset */
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(getiterfunc)enum_getiter, /* tp_iter */
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(iternextfunc)enum_next, /* tp_iternext */
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enum_methods, /* tp_methods */
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0, /* tp_members */
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0, /* tp_getset */
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0, /* tp_base */
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0, /* tp_dict */
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0, /* tp_descr_get */
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0, /* tp_descr_set */
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0, /* tp_dictoffset */
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0, /* tp_init */
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PyType_GenericAlloc, /* tp_alloc */
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enum_new, /* tp_new */
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PyObject_GC_Del, /* tp_free */
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};

‎Python/bltinmodule.c‎

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@@ -1864,6 +1864,7 @@ _PyBuiltin_Init(void)
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SETBUILTIN("complex", &PyComplex_Type);
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#endif
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SETBUILTIN("dict", &PyDict_Type);
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SETBUILTIN("enumerate", &PyEnum_Type);
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SETBUILTIN("float", &PyFloat_Type);
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SETBUILTIN("property", &PyProperty_Type);
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SETBUILTIN("int", &PyInt_Type);

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