字典物件
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PyDictObject

   "PyObject" 子型態代表一個 Python 字典物件。

PyTypeObject PyDict_Type

   "PyTypeObject" 實例代表一個 Python 字典型態。此與 Python 層中的
   "dict" 為同一個物件。

int PyDict_Check(PyObject *p)

   若 *p* 是一個字典物件或字典的子型態實例則會回傳 true。

int PyDict_CheckExact(PyObject *p)

   若 *p* 是一個字典物件但並不是一個字典子型態的實例，則回傳 true。

PyObject* PyDict_New()
    *Return value: New reference.*

   返回一个新的空字典，失败时返回 "NULL"。

PyObject* PyDictProxy_New(PyObject *mapping)
    *Return value: New reference.*

   Return a "types.MappingProxyType" object for a mapping which
   enforces read-only behavior.  This is normally used to create a
   view to prevent modification of the dictionary for non-dynamic
   class types.

void PyDict_Clear(PyObject *p)

   Empty an existing dictionary of all key-value pairs.

int PyDict_Contains(PyObject *p, PyObject *key)

   Determine if dictionary *p* contains *key*.  If an item in *p* is
   matches *key*, return "1", otherwise return "0".  On error, return
   "-1". This is equivalent to the Python expression "key in p".

PyObject* PyDict_Copy(PyObject *p)
    *Return value: New reference.*

   Return a new dictionary that contains the same key-value pairs as
   *p*.

int PyDict_SetItem(PyObject *p, PyObject *key, PyObject *val)

   Insert *value* into the dictionary *p* with a key of *key*.  *key*
   must be *hashable*; if it isn't, "TypeError" will be raised. Return
   "0" on success or "-1" on failure.

int PyDict_SetItemString(PyObject *p, const char *key, PyObject *val)

   Insert *value* into the dictionary *p* using *key* as a key. *key*
   should be a "const char*".  The key object is created using
   "PyUnicode_FromString(key)".  Return "0" on success or "-1" on
   failure.

int PyDict_DelItem(PyObject *p, PyObject *key)

   Remove the entry in dictionary *p* with key *key*. *key* must be
   hashable; if it isn't, "TypeError" is raised.  Return "0" on
   success or "-1" on failure.

int PyDict_DelItemString(PyObject *p, const char *key)

   Remove the entry in dictionary *p* which has a key specified by the
   string *key*.  Return "0" on success or "-1" on failure.

PyObject* PyDict_GetItem(PyObject *p, PyObject *key)
    *Return value: Borrowed reference.*

   从字典 *p* 中返回以 *key* 为键的对象。 如果键名 *key* 不存在但 *没
   有* 设置一个异常则返回 "NULL"。

   需要注意的是，调用 "__hash__()" 和 "__eq__()" 方法产生的异常不会被
   抛出。改用 "PyDict_GetItemWithError()" 获得错误报告。

PyObject* PyDict_GetItemWithError(PyObject *p, PyObject *key)
    *Return value: Borrowed reference.*

   "PyDict_GetItem()" 的变种，它不会屏蔽异常。 当异常发生时将返回
   "NULL" **并且** 设置一个异常。 如果键不存在则返回 "NULL" **并且不会
   ** 设置一个异常。

PyObject* PyDict_GetItemString(PyObject *p, const char *key)
    *Return value: Borrowed reference.*

   This is the same as "PyDict_GetItem()", but *key* is specified as a
   "const char*", rather than a "PyObject*".

   需要注意的是，调用 "__hash__()" 、 "__eq__()" 方法和创建一个临时的
   字符串对象时产生的异常不会被抛出。改用 "PyDict_GetItemWithError()"
   获得错误报告。

PyObject* PyDict_SetDefault(PyObject *p, PyObject *key, PyObject *defaultobj)
    *Return value: Borrowed reference.*

   This is the same as the Python-level "dict.setdefault()".  If
   present, it returns the value corresponding to *key* from the
   dictionary *p*.  If the key is not in the dict, it is inserted with
   value *defaultobj* and *defaultobj* is returned.  This function
   evaluates the hash function of *key* only once, instead of
   evaluating it independently for the lookup and the insertion.

   3.4 版新加入.

PyObject* PyDict_Items(PyObject *p)
    *Return value: New reference.*

   Return a "PyListObject" containing all the items from the
   dictionary.

PyObject* PyDict_Keys(PyObject *p)
    *Return value: New reference.*

   Return a "PyListObject" containing all the keys from the
   dictionary.

PyObject* PyDict_Values(PyObject *p)
    *Return value: New reference.*

   Return a "PyListObject" containing all the values from the
   dictionary *p*.

Py_ssize_t PyDict_Size(PyObject *p)

   Return the number of items in the dictionary.  This is equivalent
   to "len(p)" on a dictionary.

int PyDict_Next(PyObject *p, Py_ssize_t *ppos, PyObject **pkey, PyObject **pvalue)

   迭代字典 *p* 中的所有键值对。 在第一次调用此函数开始迭代之前，由
   *ppos* 所引用的 "Py_ssize_t" 必须初始化为 "0"；该函数将为字典中的每
   个键值对返回真值，一旦所有键值对报告完毕则返回假值。 形参 *pkey* 和
   *pvalue* 应当指向 "PyObject*" 变量，它们将分别使用每个键和值来填充
   ，或者也可以为 "NULL"。 通过它们返回的任何引用都是暂借的。 *ppos*
   在迭代期间不应被更改。 它的值表示内部字典结构中的偏移量，并且由于结
   构是稀疏的，因此偏移量并不连续。

   For example:

      PyObject *key, *value;
      Py_ssize_t pos = 0;

      while (PyDict_Next(self->dict, &pos, &key, &value)) {
          /* do something interesting with the values... */
          ...
      }

   The dictionary *p* should not be mutated during iteration.  It is
   safe to modify the values of the keys as you iterate over the
   dictionary, but only so long as the set of keys does not change.
   For example:

      PyObject *key, *value;
      Py_ssize_t pos = 0;

      while (PyDict_Next(self->dict, &pos, &key, &value)) {
          long i = PyLong_AsLong(value);
          if (i == -1 && PyErr_Occurred()) {
              return -1;
          }
          PyObject *o = PyLong_FromLong(i + 1);
          if (o == NULL)
              return -1;
          if (PyDict_SetItem(self->dict, key, o) < 0) {
              Py_DECREF(o);
              return -1;
          }
          Py_DECREF(o);
      }

int PyDict_Merge(PyObject *a, PyObject *b, int override)

   Iterate over mapping object *b* adding key-value pairs to
   dictionary *a*. *b* may be a dictionary, or any object supporting
   "PyMapping_Keys()" and "PyObject_GetItem()". If *override* is true,
   existing pairs in *a* will be replaced if a matching key is found
   in *b*, otherwise pairs will only be added if there is not a
   matching key in *a*. Return "0" on success or "-1" if an exception
   was raised.

int PyDict_Update(PyObject *a, PyObject *b)

   This is the same as "PyDict_Merge(a, b, 1)" in C, and is similar to
   "a.update(b)" in Python except that "PyDict_Update()" doesn't fall
   back to the iterating over a sequence of key value pairs if the
   second argument has no "keys" attribute.  Return "0" on success or
   "-1" if an exception was raised.

int PyDict_MergeFromSeq2(PyObject *a, PyObject *seq2, int override)

   Update or merge into dictionary *a*, from the key-value pairs in
   *seq2*. *seq2* must be an iterable object producing iterable
   objects of length 2, viewed as key-value pairs.  In case of
   duplicate keys, the last wins if *override* is true, else the first
   wins. Return "0" on success or "-1" if an exception was raised.
   Equivalent Python (except for the return value):

      def PyDict_MergeFromSeq2(a, seq2, override):
          for key, value in seq2:
              if override or key not in a:
                  a[key] = value

int PyDict_ClearFreeList()

   Clear the free list. Return the total number of freed items.

   3.3 版新加入.
