字典对象¶

PyDictObject¶: 这个 PyObject 的子类型代表一个Python字典对象。

PyTypeObject PyDict_Type¶: This instance of PyTypeObject represents the Python dictionary type. This is exposed to Python programs as dict and types.DictType.

int PyDict_Check(PyObject *p)¶: 如果 p 是字典对象或者字典类型的子类型的实例，则返回真。

在 2.2 版更改: Allowed subtypes to be accepted.

int PyDict_CheckExact(PyObject *p)¶: 如果 p 是字典对象但不是字典类型的子类型的实例，则返回真。

2.4 新版功能.

PyObject* PyDict_New()¶: Return value: New reference.
返回一个新的空字典或者返回 NULL 表示失败。

PyObject* PyDictProxy_New(PyObject *dict)¶: Return value: New reference.
Return a proxy object for a mapping which enforces read-only behavior. This is normally used to create a proxy to prevent modification of the dictionary for non-dynamic class types.

2.2 新版功能.

void PyDict_Clear(PyObject *p)¶: 清空现有字典的所有键值对。

int PyDict_Contains(PyObject *p, PyObject *key)¶: 确定 key 是否包含在字典 p 中。如果 key 匹配上 p 的某一项，则返回 1 ，否则返回 0 。返回 -1 表示出错。这等同于Python表达式 key in p 。

2.4 新版功能.

PyObject* PyDict_Copy(PyObject *p)¶: Return value: New reference.
返回与 p 包含相同键值对的新字典。

1.6 新版功能.

int PyDict_SetItem(PyObject *p, PyObject *key, PyObject *val)¶: 使用 key 作为键将 value 插入字典 p 。 key 必须为 hashable ；如果不是，会抛出 TypeError 异常。成功返回 0 ，失败返回 -1 。

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 char*. The key object is created using PyString_FromString(key). Return 0 on success or -1 on failure.

int PyDict_DelItem(PyObject *p, PyObject *key)¶: 使用键 key 删除字典 p 中的条目。 key 必须是可哈希的；如果不是，则抛出 TypeError 异常。成功时返回 0 ，失败时返回 -1 。

int PyDict_DelItemString(PyObject *p, char *key)¶: 删除字典 p 中的条目，其中包含由字符串 key 指定的键。成功时返回“0，失败时返回“-1”。

PyObject* PyDict_GetItem(PyObject *p, PyObject *key)¶: Return value: Borrowed reference.
返回字典 p 中 key 作为键的对象。如果键 key 不存在则返回 NULL ，但可以使用 without 设置例外。

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 char*, rather than a PyObject*.

PyObject* PyDict_Items(PyObject *p)¶: Return value: New reference.
Return a PyListObject containing all the items from the dictionary, as in the dictionary method dict.items().

PyObject* PyDict_Keys(PyObject *p)¶: Return value: New reference.
Return a PyListObject containing all the keys from the dictionary, as in the dictionary method dict.keys().

PyObject* PyDict_Values(PyObject *p)¶: Return value: New reference.
Return a PyListObject containing all the values from the dictionary p, as in the dictionary method dict.values().

Py_ssize_t PyDict_Size(PyObject *p)¶: 返回字典中项目数，等价于对字典 p 使用 len(p)。

在 2.5 版更改: This function returned an int type. This might require changes in your code for properly supporting 64-bit systems.

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

Iterate over all key-value pairs in the dictionary p. The Py_ssize_t referred to by ppos must be initialized to 0 prior to the first call to this function to start the iteration; the function returns true for each pair in the dictionary, and false once all pairs have been reported. The parameters pkey and pvalue should either point to PyObject* variables that will be filled in with each key and value, respectively, or may be NULL. Any references returned through them are borrowed. ppos should not be altered during iteration. Its value represents offsets within the internal dictionary structure, and since the structure is sparse, the offsets are not consecutive.

例如:

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 (since Python 2.1) 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)) {
    int i = PyInt_AS_LONG(value) + 1;
    PyObject *o = PyInt_FromLong(i);
    if (o == NULL)
        return -1;
    if (PyDict_SetItem(self->dict, key, o) < 0) {
        Py_DECREF(o);
        return -1;
    }
    Py_DECREF(o);
}

在 2.5 版更改: This function used an int * type for ppos. This might require changes in your code for properly supporting 64-bit systems.

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.

2.2 新版功能.

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.

2.2 新版功能.

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

2.2 新版功能.

字典对象¶

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