Dictionary Objects¶
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PyTypeObject
PyDict_Type
¶ This instance of
PyTypeObject
represents the Python dictionary type. This is the same object asdict
in the Python layer.
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int
PyDict_Check
(PyObject *p)¶ Return true if p is a dict object or an instance of a subtype of the dict type.
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int
PyDict_CheckExact
(PyObject *p)¶ Return true if p is a dict object, but not an instance of a subtype of the dict type.
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PyObject*
PyDict_New
()¶ - Return value: New reference.
Return a new empty dictionary, or NULL on failure.
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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.
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int
PyDict_Contains
(PyObject *p, PyObject *key)¶ Determine if dictionary p contains key. If an item in p is matches key, return
1
, otherwise return0
. On error, return-1
. This is equivalent to the Python expressionkey in p
.
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PyObject*
PyDict_Copy
(PyObject *p)¶ - Return value: New reference.
Return a new dictionary that contains the same key-value pairs as p.
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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. Return0
on success or-1
on failure.
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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.
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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. Return0
on success or-1
on failure.
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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.
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PyObject*
PyDict_GetItem
(PyObject *p, PyObject *key)¶ - Return value: Borrowed reference.
Return the object from dictionary p which has a key key. Return NULL if the key key is not present, but without setting an exception.
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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.
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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*
.
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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.Nuevo en la versión 3.4.
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PyObject*
PyDict_Items
(PyObject *p)¶ - Return value: New reference.
Return a
PyListObject
containing all the items from the dictionary.
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PyObject*
PyDict_Keys
(PyObject *p)¶ - Return value: New reference.
Return a
PyListObject
containing all the keys from the dictionary.
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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.
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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.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); }
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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.
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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.
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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.
Nuevo en la versión 3.3.