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type PyDictObject

此子类型的 PyObject represents a Python dictionary object.

PyTypeObject PyDict_Type
属于 稳定 ABI (应用程序二进制接口) .

此实例的 PyTypeObject represents the Python dictionary type. This is the same object as dict 在 Python 层。

int PyDict_Check ( PyObject * p )

返回 True 若 p is a dict object or an instance of a subtype of the dict type. This function always succeeds.

int PyDict_CheckExact ( PyObject * p )

返回 True 若 p is a dict object, but not an instance of a subtype of the dict type. This function always succeeds.

PyObject * PyDict_New ( )
返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

Return a new empty dictionary, or NULL 当故障时。

PyObject * PyDictProxy_New ( PyObject * 映射 )
返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

返回 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 )
属于 稳定 ABI (应用程序二进制接口) .

Empty an existing dictionary of all key-value pairs.

int PyDict_Contains ( PyObject * p , PyObject * key )
属于 稳定 ABI (应用程序二进制接口) .

Determine if dictionary p 包含 key . If an item in p is matches key ，返回 1 ，否则返回 0 . On error, return -1 . This is equivalent to the Python expression key in p .

PyObject * PyDict_Copy ( PyObject * p )
返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

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

int PyDict_SetItem ( PyObject * p , PyObject * key , PyObject * val )
属于 稳定 ABI (应用程序二进制接口) .

插入 val into the dictionary p with a key of key . key 必须为 hashable ; if it isn’t, TypeError will be raised. Return 0 当成功时或 -1 on failure. This function does not steal a reference to val .

int PyDict_SetItemString ( PyObject * p , const char * key , PyObject * val )
属于 稳定 ABI (应用程序二进制接口) .

这如同 PyDict_SetItem() ，但 key is specified as a const char * UTF-8 encoded bytes string, rather than a PyObject * .

int PyDict_DelItem ( PyObject * p , PyObject * key )
属于 稳定 ABI (应用程序二进制接口) .

Remove the entry in dictionary p 采用键 key . key 必须为 hashable ; if it isn’t, TypeError 被引发。若 key is not in the dictionary, KeyError is raised. Return 0 当成功时或 -1 当故障时。

int PyDict_DelItemString ( PyObject * p , const char * key )
属于 稳定 ABI (应用程序二进制接口) .

这如同 PyDict_DelItem() ，但 key is specified as a const char * UTF-8 encoded bytes string, rather than a PyObject * .

PyObject * PyDict_GetItem ( PyObject * p , PyObject * key )
返回值：借位引用。 属于 稳定 ABI (应用程序二进制接口) .

Return the object from dictionary p which has a key key 。返回 NULL if the key key is not present, but without setting an exception.

注意

Exceptions that occur while this calls __hash__() and __eq__() methods are silently ignored. Prefer the PyDict_GetItemWithError() function instead.

3.10 版改变： Calling this API without GIL held had been allowed for historical reason. It is no longer allowed.

PyObject * PyDict_GetItemWithError ( PyObject * p , PyObject * key )
返回值：借位引用。 属于 稳定 ABI (应用程序二进制接口) .

Variant of PyDict_GetItem() that does not suppress exceptions. Return NULL with an exception set if an exception occurred. Return NULL without an exception set if the key wasn’t present.

PyObject * PyDict_GetItemString ( PyObject * p , const char * key )
返回值：借位引用。 属于 稳定 ABI (应用程序二进制接口) .

这如同 PyDict_GetItem() ，但 key is specified as a const char * UTF-8 encoded bytes string, rather than a PyObject * .

注意

Exceptions that occur while this calls __hash__() and __eq__() methods or while creating the temporary str object are silently ignored. Prefer using the PyDict_GetItemWithError() function with your own PyUnicode_FromString() key 代替。

PyObject * PyDict_SetDefault ( PyObject * p , PyObject * key , PyObject * defaultobj )
返回值：借位引用。

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.

Added in version 3.4.

PyObject * PyDict_Items ( PyObject * p )
返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

返回 PyListObject containing all the items from the dictionary.

PyObject * PyDict_Keys ( PyObject * p )
返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

返回 PyListObject containing all the keys from the dictionary.

PyObject * PyDict_Values ( PyObject * p )
返回值：新引用。 属于 稳定 ABI (应用程序二进制接口) .

返回 PyListObject containing all the values from the dictionary p .

Py_ssize_t PyDict_Size ( PyObject * p )
属于 稳定 ABI (应用程序二进制接口) .

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 )
属于 稳定 ABI (应用程序二进制接口) .

Iterate over all key-value pairs in the dictionary p 。 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 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 )
属于 稳定 ABI (应用程序二进制接口) .

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() 。若 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 。返回 0 当成功时或 -1 if an exception was raised.

int PyDict_Update ( PyObject * a , PyObject * b )
属于 稳定 ABI (应用程序二进制接口) .

这如同 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 当成功时或 -1 if an exception was raised.

int PyDict_MergeFromSeq2 ( PyObject * a , PyObject * seq2 , int override )
属于 稳定 ABI (应用程序二进制接口) .

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 当成功时或 -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_AddWatcher ( PyDict_WatchCallback callback )

注册 callback as a dictionary watcher. Return a non-negative integer id which must be passed to future calls to PyDict_Watch() . In case of error (e.g. no more watcher IDs available), return -1 and set an exception.

3.12 版添加。

int PyDict_ClearWatcher ( int watcher_id )

Clear watcher identified by watcher_id previously returned from PyDict_AddWatcher() 。返回 0 当成功时， -1 on error (e.g. if the given watcher_id was never registered.)

3.12 版添加。

int PyDict_Watch ( int watcher_id , PyObject * dict )

Mark dictionary dict as watched. The callback granted watcher_id by PyDict_AddWatcher() will be called when dict is modified or deallocated. Return 0 当成功时或 -1 当出错时。

3.12 版添加。

int PyDict_Unwatch ( int watcher_id , PyObject * dict )

Mark dictionary dict as no longer watched. The callback granted watcher_id by PyDict_AddWatcher() will no longer be called when dict is modified or deallocated. The dict must previously have been watched by this watcher. Return 0 当成功时或 -1 当出错时。

3.12 版添加。

type PyDict_WatchEvent

Enumeration of possible dictionary watcher events: PyDict_EVENT_ADDED , PyDict_EVENT_MODIFIED , PyDict_EVENT_DELETED , PyDict_EVENT_CLONED , PyDict_EVENT_CLEARED ，或 PyDict_EVENT_DEALLOCATED .

3.12 版添加。

typedef int ( * PyDict_WatchCallback ) ( PyDict_WatchEvent event , PyObject * dict , PyObject * key , PyObject * new_value )

Type of a dict watcher callback function.

若 event is PyDict_EVENT_CLEARED or PyDict_EVENT_DEALLOCATED , both key and new_value 将是 NULL 。若 event is PyDict_EVENT_ADDED or PyDict_EVENT_MODIFIED , new_value will be the new value for key 。若 event is PyDict_EVENT_DELETED , key is being deleted from the dictionary and new_value 将是 NULL .

PyDict_EVENT_CLONED occurs when dict was previously empty and another dict is merged into it. To maintain efficiency of this operation, per-key PyDict_EVENT_ADDED events are not issued in this case; instead a single PyDict_EVENT_CLONED is issued, and key will be the source dictionary.

The callback may inspect but must not modify dict ; doing so could have unpredictable effects, including infinite recursion. Do not trigger Python code execution in the callback, as it could modify the dict as a side effect.

若 event is PyDict_EVENT_DEALLOCATED , taking a new reference in the callback to the about-to-be-destroyed dictionary will resurrect it and prevent it from being freed at this time. When the resurrected object is destroyed later, any watcher callbacks active at that time will be called again.

Callbacks occur before the notified modification to dict takes place, so the prior state of dict can be inspected.

If the callback sets an exception, it must return -1 ; this exception will be printed as an unraisable exception using PyErr_WriteUnraisable() . Otherwise it should return 0 .

There may already be a pending exception set on entry to the callback. In this case, the callback should return 0 with the same exception still set. This means the callback may not call any other API that can set an exception unless it saves and clears the exception state first, and restores it before returning.

3.12 版添加。

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  1. 首页
  2. Python 3.12.4
  3. 索引
  4. 模块
  5. 下一
  6. 上一
  7. Python/C API 参考手册
  8. 具体对象层
  9. 字典对象