字典对象¶
-
PyTypeObject
PyDict_Type
¶ Python字典类型表示为
PyTypeObject
的实例。这与Python层面的dict
是相同的对象。
-
PyObject*
PyDictProxy_New
(PyObject *mapping)¶ - Return value: New reference.
返回
types.MappingProxyType
对象,用于强制执行只读行为的映射。这通常用于创建视图以防止修改非动态类类型的字典。
-
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
。
-
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 usingPyUnicode_FromString(key)
. Return0
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, const 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”。
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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。
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PyObject*
PyDict_GetItemWithError
(PyObject *p, PyObject *key)¶ 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)¶ - Return value: Borrowed reference.
This is the same as
PyDict_GetItem()
, but key is specified as achar*
, rather than aPyObject*
.
-
PyObject*
PyDict_SetDefault
(PyObject *p, PyObject *key, PyObject *default)¶ - 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 新版功能.
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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.
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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)¶ Iterate over all key-value pairs in the dictionary p. The
Py_ssize_t
referred to by ppos must be initialized to0
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 toPyObject*
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); }
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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()
andPyObject_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. Return0
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 toa.update(b)
in Python except thatPyDict_Update()
doesn’t fall back to the iterating over a sequence of key value pairs if the second argument has no “keys” attribute. Return0
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
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int
PyDict_ClearFreeList
()¶ Clear the free list. Return the total number of freed items.
3.3 新版功能.