[전희선] 11주차 미션 제출

8th_members/전희선/11주차.md

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+### set 구조체 분석
+```c++
+// Include/setobject.h
+PyAPI_DATA(PyTypeObject) PySet_Type;
+```
+```c++
+// Objects/setobject.c
+PyTypeObject PySet_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    "set",                              /* tp_name */
+    sizeof(PySetObject),                /* tp_basicsize */
+    0,                                  /* tp_itemsize */
+    /* methods */
+    (destructor)set_dealloc,            /* tp_dealloc */
+    0,                                  /* tp_vectorcall_offset */
+    0,                                  /* tp_getattr */
+    0,                                  /* tp_setattr */
+    0,                                  /* tp_as_async */
+    (reprfunc)set_repr,                 /* tp_repr */
+    &set_as_number,                     /* tp_as_number */
+    &set_as_sequence,                   /* tp_as_sequence */
+    0,                                  /* tp_as_mapping */
+    PyObject_HashNotImplemented,        /* 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 */
+    set_doc,                            /* tp_doc */
+    (traverseproc)set_traverse,         /* tp_traverse */
+    (inquiry)set_clear_internal,        /* tp_clear */
+    (richcmpfunc)set_richcompare,       /* tp_richcompare */
+    offsetof(PySetObject, weakreflist), /* tp_weaklistoffset */
+    (getiterfunc)set_iter,              /* tp_iter */
+    0,                                  /* tp_iternext */
+    set_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 */
+    (initproc)set_init,                 /* tp_init */
+    PyType_GenericAlloc,                /* tp_alloc */
+    set_new,                            /* tp_new */
+    PyObject_GC_Del,                    /* tp_free */
+    .tp_vectorcall = set_vectorcall,
+};
+```
+#### set_new
+```c++
+// Objects/setobject.c
+static PyObject *
+set_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+{
+    return make_new_set(type, NULL);
+}
+```
+```c++
+static PyObject *
+make_new_set(PyTypeObject *type, PyObject *iterable)
+{
+    assert(PyType_Check(type));
+    PySetObject *so;
+
+    so = (PySetObject *)type->tp_alloc(type, 0);  // 메모리 할당
+    if (so == NULL)
+        return NULL;
+
+    so->fill = 0;                  // 해시 테이블에서 사용중인 slot 수 (삭제된 항목 포함)
+    so->used = 0;                  // 실제 사용중인 항목 수
+    so->mask = PySet_MINSIZE - 1;  // 비트 마스크: 해시 테이블 크기 - 1
+    so->table = so->smalltable;    // 내장 작은 테이블 사용
+    so->hash = -1;                 // 해시값 (-1: 아직 계산되지 않음을 나타냄)
+    so->finger = 0;                // 순회 시 사용하는 인덱스
+    so->weakreflist = NULL;        // 약한 참조 리스트
+
+    // iterable 제공된 경우 set에 추가
+    if (iterable != NULL) {
+        if (set_update_internal(so, iterable)) {
+            Py_DECREF(so);
+            return NULL;
+        }
+    }
+
+    return (PyObject *)so;
+}
+```
+```c++
+static int
+set_update_internal(PySetObject *so, PyObject *other)
+{
+    PyObject *key, *it;
+
+    if (PyAnySet_Check(other))
+        return set_merge(so, other);
+
+    if (PyDict_CheckExact(other)) {
+        PyObject *value;
+        Py_ssize_t pos = 0;
+        Py_hash_t hash;
+        Py_ssize_t dictsize = PyDict_GET_SIZE(other);
+
+        /* Do one big resize at the start, rather than
+        * incrementally resizing as we insert new keys.  Expect
+        * that there will be no (or few) overlapping keys.
+        */
+        if (dictsize < 0)
+            return -1;
+        if ((so->fill + dictsize)*5 >= so->mask*3) {
+            if (set_table_resize(so, (so->used + dictsize)*2) != 0)
+                return -1;
+        }
+        while (_PyDict_Next(other, &pos, &key, &value, &hash)) {
+            if (set_add_entry(so, key, hash))
+                return -1;
+        }
+        return 0;
+    }
+
+    it = PyObject_GetIter(other);
+    if (it == NULL)
+        return -1;
+
+    while ((key = PyIter_Next(it)) != NULL) {
+        if (set_add_key(so, key)) {
+            Py_DECREF(it);
+            Py_DECREF(key);
+            return -1;
+        }
+        Py_DECREF(key);
+    }
+    Py_DECREF(it);
+    if (PyErr_Occurred())
+        return -1;
+    return 0;
+}
+```