- 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.
diff --git a/Include/Python.h b/Include/Python.h
index f440a3a..e3addc7 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -91,6 +91,7 @@
#include "tupleobject.h"
#include "listobject.h"
#include "dictobject.h"
+#include "enumobject.h"
#include "methodobject.h"
#include "moduleobject.h"
#include "funcobject.h"
diff --git a/Include/enumobject.h b/Include/enumobject.h
new file mode 100644
index 0000000..df20fb0
--- /dev/null
+++ b/Include/enumobject.h
@@ -0,0 +1,16 @@
+#ifndef Py_ENUMOBJECT_H
+#define Py_ENUMOBJECT_H
+
+/* Enumerate Object */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern DL_IMPORT(PyTypeObject) PyEnum_Type;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* !Py_ENUMOBJECT_H */
diff --git a/Lib/test/test_enumerate.py b/Lib/test/test_enumerate.py
new file mode 100644
index 0000000..b0d442e
--- /dev/null
+++ b/Lib/test/test_enumerate.py
@@ -0,0 +1,118 @@
+from __future__ import generators
+import unittest
+
+import test_support
+
+seq, res = 'abc', [(0,'a'), (1,'b'), (2,'c')]
+
+class G:
+ 'Sequence using __getitem__'
+ def __init__(self, seqn):
+ self.seqn = seqn
+ def __getitem__(self, i):
+ return self.seqn[i]
+
+class I:
+ 'Sequence using iterator protocol'
+ def __init__(self, seqn):
+ self.seqn = seqn
+ self.i = 0
+ def __iter__(self):
+ return self
+ def next(self):
+ if self.i >= len(self.seqn): raise StopIteration
+ v = self.seqn[self.i]
+ self.i += 1
+ return v
+
+class Ig:
+ 'Sequence using iterator protocol defined with a generator'
+ def __init__(self, seqn):
+ self.seqn = seqn
+ self.i = 0
+ def __iter__(self):
+ for val in self.seqn:
+ yield val
+
+class X:
+ 'Missing __getitem__ and __iter__'
+ def __init__(self, seqn):
+ self.seqn = seqn
+ self.i = 0
+ def next(self):
+ if self.i >= len(self.seqn): raise StopIteration
+ v = self.seqn[self.i]
+ self.i += 1
+ return v
+
+class E:
+ 'Test propagation of exceptions'
+ def __init__(self, seqn):
+ self.seqn = seqn
+ self.i = 0
+ def __iter__(self):
+ return self
+ def next(self):
+ 3/0
+
+class N:
+ 'Iterator missing next()'
+ def __init__(self, seqn):
+ self.seqn = seqn
+ self.i = 0
+ def __iter__(self):
+ return self
+
+class EnumerateTestCase(unittest.TestCase):
+
+ enum = enumerate
+
+ def test_basicfunction(self):
+ self.assertEqual(type(self.enum(seq)), self.enum)
+ e = self.enum(seq)
+ self.assertEqual(iter(e), e)
+ self.assertEqual(list(self.enum(seq)), res)
+ self.enum.__doc__
+
+ def test_getitemseqn(self):
+ self.assertEqual(list(self.enum(G(seq))), res)
+ e = self.enum(G(''))
+ self.assertRaises(StopIteration, e.next)
+
+ def test_iteratorseqn(self):
+ self.assertEqual(list(self.enum(I(seq))), res)
+ e = self.enum(I(''))
+ self.assertRaises(StopIteration, e.next)
+
+ def test_iteratorgenerator(self):
+ self.assertEqual(list(self.enum(Ig(seq))), res)
+ e = self.enum(Ig(''))
+ self.assertRaises(StopIteration, e.next)
+
+ def test_noniterable(self):
+ self.assertRaises(TypeError, self.enum, X(seq))
+
+ def test_illformediterable(self):
+ self.assertRaises(TypeError, list, self.enum(N(seq)))
+
+ def test_exception_propagation(self):
+ self.assertRaises(ZeroDivisionError, list, self.enum(E(seq)))
+
+class MyEnum(enumerate):
+ pass
+
+class SubclassTestCase(EnumerateTestCase):
+
+ enum = MyEnum
+
+def suite():
+ suite = unittest.TestSuite()
+ suite.addTest(unittest.makeSuite(EnumerateTestCase))
+ suite.addTest(unittest.makeSuite(SubclassTestCase))
+ return suite
+
+def test_main():
+ test_support.run_suite(suite())
+
+if __name__ == "__main__":
+ test_main()
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 9ad1c0a..9ec4fa6 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -257,6 +257,7 @@
Objects/cobject.o \
Objects/complexobject.o \
Objects/descrobject.o \
+ Objects/enumobject.o \
Objects/fileobject.o \
Objects/floatobject.o \
Objects/frameobject.o \
@@ -443,6 +444,7 @@
Include/complexobject.h \
Include/descrobject.h \
Include/dictobject.h \
+ Include/enumobject.h \
Include/fileobject.h \
Include/floatobject.h \
Include/funcobject.h \
diff --git a/Misc/NEWS b/Misc/NEWS
index c63db58..d83d7b2 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -6,6 +6,10 @@
Core and builtins
+- 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.
+
- The assert statement no longer tests __debug__ at runtime. This means
that assert statements cannot be disabled by assigning a false value
to __debug__.
diff --git a/Objects/enumobject.c b/Objects/enumobject.c
new file mode 100644
index 0000000..1964956
--- /dev/null
+++ b/Objects/enumobject.c
@@ -0,0 +1,139 @@
+/* enumerate object */
+
+#include "Python.h"
+
+typedef struct {
+ PyObject_HEAD
+ long en_index; /* current index of enumeration */
+ PyObject* en_sit; /* secondary iterator of enumeration */
+} enumobject;
+
+PyTypeObject PyEnum_Type;
+
+static PyObject *
+enum_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+ enumobject *en;
+ PyObject *seq = NULL;
+ static char *kwlist[] = {"sequence", 0};
+
+ if (!PyArg_ParseTupleAndKeywords(args, kwds, "O:enumerate", kwlist,
+ &seq))
+ return NULL;
+
+ en = (enumobject *)type->tp_alloc(type, 0);
+ if (en == NULL)
+ return NULL;
+ en->en_index = 0;
+ en->en_sit = PyObject_GetIter(seq);
+ if (en->en_sit == NULL) {
+ Py_DECREF(en);
+ return NULL;
+ }
+ return (PyObject *)en;
+}
+
+static void
+enum_dealloc(enumobject *en)
+{
+ PyObject_GC_UnTrack(en);
+ Py_XDECREF(en->en_sit);
+ en->ob_type->tp_free(en);
+}
+
+static int
+enum_traverse(enumobject *en, visitproc visit, void *arg)
+{
+ if (en->en_sit)
+ return visit(en->en_sit, arg);
+ return 0;
+}
+
+static PyObject *
+enum_next(enumobject *en)
+{
+ PyObject *result;
+ PyObject *next_index;
+
+ PyObject *next_item = PyIter_Next(en->en_sit);
+ if (next_item == NULL)
+ return NULL;
+
+ result = PyTuple_New(2);
+ if (result == NULL) {
+ Py_DECREF(next_item);
+ return NULL;
+ }
+
+ next_index = PyInt_FromLong(en->en_index++);
+ if (next_index == NULL) {
+ Py_DECREF(next_item);
+ Py_DECREF(result);
+ return NULL;
+ }
+
+ PyTuple_SET_ITEM(result, 0, next_index);
+ PyTuple_SET_ITEM(result, 1, next_item);
+ return result;
+}
+
+static PyObject *
+enum_getiter(PyObject *en)
+{
+ Py_INCREF(en);
+ return en;
+}
+
+static PyMethodDef enum_methods[] = {
+ {"next", (PyCFunction)enum_next, METH_NOARGS,
+ "return the next (index, value) pair, or raise StopIteration"},
+ {NULL, NULL} /* sentinel */
+};
+
+static char enum_doc[] =
+ "enumerate(iterable) -> create an enumerating-iterator";
+
+PyTypeObject PyEnum_Type = {
+ PyObject_HEAD_INIT(&PyType_Type)
+ 0, /* ob_size */
+ "enumerate", /* tp_name */
+ sizeof(enumobject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)enum_dealloc, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+ Py_TPFLAGS_BASETYPE, /* tp_flags */
+ enum_doc, /* tp_doc */
+ (traverseproc)enum_traverse, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ (getiterfunc)enum_getiter, /* tp_iter */
+ (iternextfunc)enum_next, /* tp_iternext */
+ enum_methods, /* tp_methods */
+ 0, /* tp_members */
+ 0, /* tp_getset */
+ 0, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+ 0, /* tp_dictoffset */
+ 0, /* tp_init */
+ PyType_GenericAlloc, /* tp_alloc */
+ enum_new, /* tp_new */
+ PyObject_GC_Del, /* tp_free */
+};
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 680152d..06d8616 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -1864,6 +1864,7 @@
SETBUILTIN("complex", &PyComplex_Type);
#endif
SETBUILTIN("dict", &PyDict_Type);
+ SETBUILTIN("enumerate", &PyEnum_Type);
SETBUILTIN("float", &PyFloat_Type);
SETBUILTIN("property", &PyProperty_Type);
SETBUILTIN("int", &PyInt_Type);