tup = tuple((1, 2, 3, 4, 5))
print("值:%r,類型：%r" % (tup, type(tup)))

# 值:(1, 2, 3, 4, 5),類型：<class 'tuple'>

tup = 1, 2, 3, 4, 5
print("值:%r,類型：%r" % (tup, type(tup)))

# 值:(1, 2, 3, 4, 5),類型：<class 'tuple'>

tup = (1, 2, 3, 4, 5)
print("值:%r,類型：%r" % (tup, type(tup)))

# 值:(1, 2, 3, 4, 5),類型：<class 'tuple'>

tup = (1, 2, 3, 4, 5)
print("值:%r,類型：%r" % (tup, type(tup)))

# 值:(1, 2, 3, 4, 5),類型：<class 'tuple'>

tup = (1, 2, ("三", "四"))
print("值:%r,類型：%r" % (tup, type(tup)))

# 值:(1, 2, ('三', '四')),類型：<class 'tuple'>

tup = (1, 2, 3)
bTup = bool(tup)    # 布爾類型
strTup = str(tup)   # 字符串類型
liTup = list(tup)   # 列表類型
setTup = set(tup)   # 集合類型

print("值:%r,類型：%r" % (bTup, type(bTup)))
print("值:%r,類型：%r" % (strTup, type(strTup)))
print("值:%r,類型：%r" % (liTup, type(liTup)))
print("值:%r,類型：%r" % (setTup, type(setTup)))

# 值:True,類型：<class 'bool'>
# 值:'(1, 2, 3)',類型：<class 'str'>
# 值:[1, 2, 3],類型：<class 'list'>
# 值:{1, 2, 3},類型：<class 'set'>

tup = (("k1", "v1"), ("k2", "v2"), ("k3", "v3"))
dictTuple = dict(tup)

print("值:%r,類型：%r" % (dictTuple, type(dictTuple)))

# 值:{'k1': 'v1', 'k2': 'v2', 'k3': 'v3'},類型：<class 'dict'>

>>> import copy
>>> # 列表的深淺拷貝均創(chuàng)建新列表...
>>> oldLi = [1, 2, 3]
>>> id(oldLi)
4542649096
>>> li1 = copy.copy(oldLi)
>>> id(li1)
4542648840
>>> li2 = copy.deepcopy(oldLi)
>>> id(li2)
4542651208
>>> # 元組的深淺拷貝始終引用老元組
>>> oldTup = (1, 2, 3)
>>> id(oldTup)
4542652920
>>> tup1 = copy.copy(oldTup)
>>> id(tup1)
4542652920
>>> tup2 = copy.deepcopy(oldTup)
>>> id(tup2)
4542652920

>>> t = (1, 2, [30, 40])
>>> t[-1] += [50, 60]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'tuple' object does not support item assignment

>>> t
(1, 2, [30, 40, 50, 60])

tup = ("A", "B", "C", "D", "E", "F", "G")

print(len(tup))

# 7

tup = ("A", "B", "C", "D", "E", "F", "G", "A")

aInTupCount = tup.count("A")

print(aInTupCount)

# 2

tup = ("A", "B", "C", "D", "E", "F", "G", "A")

aInTupIndex = tup.index("A")

print(aInTupIndex)

# 0

tup = tuple((1, 2, 3))

>>> oldTup = (1, 2, 3)
>>> id(oldTup)
4384908128
>>> newTup = tuple(oldTup)
>>> id(newTup)
4384908128
>>>

tup = tuple([1, 2, 3])

>>> li1 = ["A", "B", "C"]
>>> tup = tuple(li1)
>>> print(id(li1[0]))
4383760656
>>> print(id(tup[0]))
4383760656
>>>

rangeObject = range(1, 101)
tup = tuple(rangeObject)

// 假如猜想的是9
// 第一步：+ 10 
// 第二步：+ (原長度+10) * 0.25
// 其實，就是增加【原長度*0.25 + 2.5】

tup = (1, 2, 3)
newSliceTup = tup[0:2]

>>> id(tup)
4384908416
>>> newSliceTup = tup[0:2]
>>> id(newSliceTup)
4384904392

del 元組1
del 元組2
del 元組3

tup = (1, 2, 3)

>>> t1 = ()
>>> id(t1)
4511088712
>>> t2 = ()
>>> id(t2)
4511088712

$ python3

Python 3.6.8 (v3.6.8:3c6b436a57, Dec 24 2018, 02:04:31)
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> v1 = (None, None, None)
>>> id(v1)
4384907696
>>> v2 = (None, None, None)
>>> id(v2)
4384908056
>>> del v1
>>> del v2   # ①
>>> v3 = (None, None, None)
>>> id(v3)   # ②
4384908056
>>> v4 = (None, None, None)
>>> id(v4)   # ③
4384907696
>>>

Py_ssize_t ob_refcnt;     // 引用計數(shù)器
Py_ssize_t ob_size;       // 數(shù)據(jù)項個數(shù)，即元組大小
PyObject *ob_item[1];     // 存儲元組中的數(shù)據(jù)項 [指針, ]

PyTuple_MAXSAVESIZE     // 相當(dāng)于圖中的 free_num ，最大20，即縱向擴展的緩存元組長度
PyTuple_MAXFREELIST     // 圖中 free_list 的橫向擴展緩存列表個數(shù)，最大2000

PyObject *
PyTuple_New(Py_ssize_t size)
{
    PyTupleObject *op;
    // 緩存相關(guān)
    Py_ssize_t i;
    
    // 元組的大小不能小于0
    if (size < 0) {
        PyErr_BadInternalCall();
        return NULL;
    }
#if PyTuple_MAXSAVESIZE > 0

    // 創(chuàng)建空元組，優(yōu)先從緩存中獲取
    // size = 0 表示這是一個空元組，從free_list[0]中獲取空元組
    if (size == 0 && free_list[0]) {
        // op就是空元組
        op = free_list[0];
        // 新增空元組引用計數(shù)器 + 1
        Py_INCREF(op);
#ifdef COUNT_ALLOCS
        tuple_zero_allocs++;
#endif
        // 返回空元組的指針
        return (PyObject *) op;
    }
    
    // 如果創(chuàng)建的不是空元組，且這個創(chuàng)建的元組數(shù)據(jù)項個數(shù)小于20，并且free_list[size]不等于空，表示有緩存
    // 則從緩存中去獲取，不再重新開辟內(nèi)存
    if (size < PyTuple_MAXSAVESIZE && (op = free_list[size]) != NULL) {
        // 拿出元組
        free_list[size] = (PyTupleObject *) op->ob_item[0];
        // num_free減1
        numfree[size]--;
#ifdef COUNT_ALLOCS
        fast_tuple_allocs++;
#endif
        /* Inline PyObject_InitVar */
        // 初始化，定義這個元組的長度為數(shù)據(jù)項個數(shù)
#ifdef Py_TRACE_REFS
        Py_SIZE(op) = size;
        // 定義類型為 tuple
        Py_TYPE(op) = &PyTuple_Type;
#endif
        // 增加一次新的引用
        _Py_NewReference((PyObject *)op);
    }
    
    // 如果是空元組
    else
#endif
    {
        // 檢查內(nèi)存情況，是否充足
        /* Check for overflow */
        if ((size_t)size > ((size_t)PY_SSIZE_T_MAX - sizeof(PyTupleObject) -
                    sizeof(PyObject *)) / sizeof(PyObject *)) {
            return PyErr_NoMemory();
        }
        // 開辟內(nèi)存，并獲得一個元組：op
        op = PyObject_GC_NewVar(PyTupleObject, &PyTuple_Type, size);
        if (op == NULL)
            return NULL;
    }
    
    // 空元組的每一個槽位都是NULL
    for (i=0; i < size; i++)
        op->ob_item[i] = NULL;
        
#if PyTuple_MAXSAVESIZE > 0
   // 緩存空元組
    if (size == 0) {
        free_list[0] = op;
        ++numfree[0];
        Py_INCREF(op);          /* extra INCREF so that this is never freed */
    }
#endif
#ifdef SHOW_TRACK_COUNT
    count_tracked++;
#endif

    // 將元組加入到GC機制中，用于內(nèi)存管理
    _PyObject_GC_TRACK(op);
    return (PyObject *) op;
}

PyObject *
PySequence_Tuple(PyObject *v)
{
    PyObject *it;  /* iter(v) */
    Py_ssize_t n;             /* guess for result tuple size */
    PyObject *result = NULL;
    Py_ssize_t j;

    if (v == NULL) {
        return null_error();
    }

    /* Special-case the common tuple and list cases, for efficiency. */
    // 如果是元組轉(zhuǎn)換元組，如 tup = (1, 2, 3) 或者 tup = ((1, 2, 3))直接返回內(nèi)存地址
    if (PyTuple_CheckExact(v)) {
        Py_INCREF(v);
        return v;
    }
    
    // 如果是列表轉(zhuǎn)換元組，則執(zhí)行PyList_AsTuple()，將列表轉(zhuǎn)換為元組
    // 如 tup = ([1, 2, 3])
    if (PyList_CheckExact(v))
        return PyList_AsTuple(v);

    /* Get iterator. */
    // 獲取迭代器， tup = (range(1, 4).__iter__())
 
    it = PyObject_GetIter(v);
    if (it == NULL)
        return NULL;

    /* Guess result size and allocate space. */
    // 猜想迭代器長度，也就是猜一下有多少個數(shù)據(jù)項
    n = PyObject_LengthHint(v, 10);
    if (n == -1)
        goto Fail;
        
    // 根據(jù)猜想的迭代器長度，進行元組的內(nèi)存開辟
    result = PyTuple_New(n);
    if (result == NULL)
        goto Fail;

    /* Fill the tuple. */
    // 將迭代器中每個數(shù)據(jù)項添加至元組中
    for (j = 0; ; ++j) {
        PyObject *item = PyIter_Next(it);
        if (item == NULL) {
            if (PyErr_Occurred())
                goto Fail;
            break;
        }
        
        //如果迭代器中數(shù)據(jù)項比猜想的多，則證明開辟內(nèi)存不足需要需要進行擴容
        if (j >= n) {
            size_t newn = (size_t)n;
            /* The over-allocation strategy can grow a bit faster
               than for lists because unlike lists the
               over-allocation isn't permanent -- we reclaim
               the excess before the end of this routine.
               So, grow by ten and then add 25%.
            */
            
            // 假如猜想的是9
            // 第一步：+ 10 
            // 第二步：+ (原長度+10) * 0.25
            // 其實，就是增加【原長度*0.25 + 2.5】
            
            newn += 10u;
            newn += newn >> 2;
            
            // 判斷是否超過了元組的數(shù)據(jù)項個數(shù)限制（sys.maxsize）
            if (newn > PY_SSIZE_T_MAX) {
                /* Check for overflow */
                PyErr_NoMemory();
                Py_DECREF(item);
                goto Fail;
            }
            n = (Py_ssize_t)newn;
            // 擴容機制
            if (_PyTuple_Resize(&result, n) != 0) {
                Py_DECREF(item);
                goto Fail;
            }
        }
        
        // 將數(shù)據(jù)項放入元組之中
        PyTuple_SET_ITEM(result, j, item);
    }

    /* Cut tuple back if guess was too large. */
    
    // 如果猜想的數(shù)據(jù)項太多，而實際上迭代器中的數(shù)據(jù)量偏少
    // 則需要對該元組進行縮容
    if (j < n &&
        _PyTuple_Resize(&result, j) != 0)
        goto Fail;

    Py_DECREF(it);
    return result;

Fail:
    Py_XDECREF(result);
    Py_DECREF(it);
    return NULL;
}

PyObject *
PyList_AsTuple(PyObject *v)
{
    PyObject *w;
    PyObject **p, **q;
    Py_ssize_t n;
    // 例如：tup = ([1, 2, 3])
    
    // 進行列表的驗證
    if (v == NULL || !PyList_Check(v)) {
        PyErr_BadInternalCall();
        return NULL;
    }
    
    // 獲取大小，即數(shù)據(jù)項個數(shù)
    n = Py_SIZE(v);
    // 開辟內(nèi)存
    w = PyTuple_New(n);
    
    // 如果是空元組
    if (w == NULL)
        return NULL;
        
    // 執(zhí)行遷徙操作
    p = ((PyTupleObject *)w)->ob_item;
    q = ((PyListObject *)v)->ob_item;
    
    // 將列表中數(shù)據(jù)項的引用，也給元組進行引用
    // 這樣列表中數(shù)據(jù)項和元組中的數(shù)據(jù)項都引用同1個對象
    while (--n >= 0) {
        // 數(shù)據(jù)項引用計數(shù) + 1
        Py_INCREF(*q);
        *p = *q;
        p++;
        q++;
    }
    
    // 返回元組
    return w;
}

PyObject *
PyTuple_GetSlice(PyObject *op, Py_ssize_t i, Py_ssize_t j)
// 切片會觸發(fā)該方法
{
    // 如果對空元組進行切片，則會拋出異常
    if (op == NULL || !PyTuple_Check(op)) {
        PyErr_BadInternalCall();
        return NULL;
    }
    // 內(nèi)部的具體實現(xiàn)方法
    return tupleslice((PyTupleObject *)op, i, j);
}

static PyObject *
tupleslice(PyTupleObject *a, Py_ssize_t ilow,
           Py_ssize_t ihigh)
{
    PyTupleObject *np;
    PyObject **src, **dest;
    Py_ssize_t i;
    Py_ssize_t len;
    
    // 計算索引位置
    if (ilow < 0)
        ilow = 0;
    if (ihigh > Py_SIZE(a))
        ihigh = Py_SIZE(a);
    if (ihigh < ilow)
        ihigh = ilow;
        
    // 如果是[:]的操作，則直接返回源元組對象a的指針，即絕對引用
    if (ilow == 0 && ihigh == Py_SIZE(a) && PyTuple_CheckExact(a)) {
        Py_INCREF(a);
        return (PyObject *)a;
    }
    
    // 初始化新的切片對象元組長度
    len = ihigh - ilow;
    
    // 開始切片，創(chuàng)建了一個新元組np
    np = (PyTupleObject *)PyTuple_New(len);
    if (np == NULL)
        return NULL;
    src = a->ob_item + ilow;
    dest = np->ob_item;
    
    // 對源元組中的數(shù)據(jù)項的引用計數(shù)+1
    for (i = 0; i < len; i++) {
        PyObject *v = src[i];
        Py_INCREF(v);
        dest[i] = v;
    }
    
    // 返回切片對象新元組np的引用
    return (PyObject *)np;
}

static void
tupledealloc(PyTupleObject *op)
{
    Py_ssize_t i;
    Py_ssize_t len =  Py_SIZE(op);
    PyObject_GC_UnTrack(op);
    Py_TRASHCAN_SAFE_BEGIN(op)
    
    // 如果元組的長度大于0，則不是一個非空元組
    if (len > 0) {
        i = len;
        // 將內(nèi)部的數(shù)據(jù)項引用計數(shù)都 - 1
        while (--i >= 0)
            Py_XDECREF(op->ob_item[i]);
#if PyTuple_MAXSAVESIZE > 0
        
        // 準(zhǔn)備緩存，判斷num_free是否小于20，并且單向鏈表中的已緩存元組個數(shù)小于2000
        if (len < PyTuple_MAXSAVESIZE &&
            numfree[len] < PyTuple_MAXFREELIST &&
            Py_TYPE(op) == &PyTuple_Type)
        {
            // 添加至鏈表頭部
            op->ob_item[0] = (PyObject *) free_list[len];
            // 將num_free + 1
            numfree[len]++;
            free_list[len] = op;
            goto done; /* return */
        }
#endif
    }
    // 內(nèi)存中進行銷毀
    Py_TYPE(op)->tp_free((PyObject *)op);
done:
    Py_TRASHCAN_SAFE_END(op)
}