PyDict_Type
¶
此实例的
PyTypeObject
represents the Python dictionary type. This is the same object as
dict
在 Python 层。
PyDict_Check
(
PyObject
*p
)
¶
返回 True 若 p is a dict object or an instance of a subtype of the dict type.
PyDict_CheckExact
(
PyObject
*p
)
¶
返回 True 若 p is a dict object, but not an instance of a subtype of the dict type.
PyDictProxy_New
(
PyObject
*mapping
)
¶
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.
PyDict_Contains
(
PyObject
*p
,
PyObject
*key
)
¶
Determine if dictionary
p
contains
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
.
PyDict_Copy
(
PyObject
*p
)
¶
Return a new dictionary that contains the same key-value pairs as p .
PyDict_SetItem
(
PyObject
*p
,
PyObject
*key
,
PyObject
*val
)
¶
Insert
value
into the dictionary
p
with a key of
key
.
key
必须是
hashable
; if it isn’t,
TypeError
will be raised. Return
0
on success or
-1
当故障时。
PyDict_SetItemString
(
PyObject
*p
, const char
*key
,
PyObject
*val
)
¶
Insert
value
into the dictionary
p
使用
key
as a key.
key
应该为
char*
. The key object is created using
PyUnicode_FromString(key)
。返回
0
on success or
-1
当故障时。
PyDict_DelItem
(
PyObject
*p
,
PyObject
*key
)
¶
Remove the entry in dictionary
p
采用键
key
.
key
must be hashable; if it isn’t,
TypeError
is raised. Return
0
on success or
-1
当故障时。
PyDict_DelItemString
(
PyObject
*p
, const char
*key
)
¶
Remove the entry in dictionary
p
which has a key specified by the string
key
。返回
0
on success or
-1
当故障时。
PyDict_GetItem
(
PyObject
*p
,
PyObject
*key
)
¶
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.
Note that exceptions which occur while calling
__hash__()
and
__eq__()
methods will get suppressed. To get error reporting use
PyDict_GetItemWithError()
代替。
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.
PyDict_GetItemString
(
PyObject
*p
, const char
*key
)
¶
这如同
PyDict_GetItem()
,但
key
is specified as a
char*
, rather than a
PyObject*
.
Note that exceptions which occur while calling
__hash__()
and
__eq__()
methods and creating a temporary string object will get suppressed. To get error reporting use
PyDict_GetItemWithError()
代替。
PyDict_SetDefault
(
PyObject
*p
,
PyObject
*key
,
PyObject
*default
)
¶
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 版新增。
PyDict_Items
(
PyObject
*p
)
¶
返回
PyListObject
containing all the items from the dictionary.
PyDict_Keys
(
PyObject
*p
)
¶
返回
PyListObject
containing all the keys from the dictionary.
PyDict_Values
(
PyObject
*p
)
¶
返回
PyListObject
containing all the values from the dictionary
p
.
PyDict_Size
(
PyObject
*p
)
¶
Return the number of items in the dictionary. This is equivalent to
len(p)
on a dictionary.
PyDict_Next
(
PyObject
*p
, Py_ssize_t
*ppos
,
PyObject
**pkey
,
PyObject
**pvalue
)
¶
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);
}
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()
。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
on success or
-1
if an exception was raised.
PyDict_Update
(
PyObject
*a
,
PyObject
*b
)
¶
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
on success or
-1
if an exception was raised.
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
PyDict_ClearFreeList
(
)
¶
Clear the free list. Return the total number of freed items.
3.3 版新增。