PyDictObject
PyObject
represents a Python dictionary object.PyDict_Type
PyTypeObject
represents the Python dictionary type. This is the same object as dict
in the Python layer.PyDict_Check
(PyObject *p)PyDict_CheckExact
(PyObject *p)PyDict_New
()Return value: New reference.
Return a new empty dictionary, or NULL
on failure.
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.
PyDict_Clear
(PyObject *p)PyDict_Contains
(PyObject *p, PyObject *key)1
, otherwise return 0
. On error, return -1
. This is equivalent to the Python expression key in p
.PyDict_Copy
(PyObject *p)Return value: New reference.
Return a new dictionary that contains the same key-value pairs as p.
PyDict_SetItem
(PyObject *p, PyObject *key, PyObject *val)TypeError
will be raised. Return 0
on success or -1
on failure. This function does not steal a reference to val.PyDict_SetItemString
(PyObject *p, const char *key, PyObject *val)const char*
. The key object is created using PyUnicode_FromString(key)
. Return 0
on success or -1
on failure. This function does not steal a reference to val.PyDict_DelItem
(PyObject *p, PyObject *key)TypeError
is raised. If key is not in the dictionary, KeyError
is raised. Return 0
on success or -1
on failure.PyDict_DelItemString
(PyObject *p, const char *key)KeyError
is raised. Return 0
on success or -1
on failure.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.
Note that exceptions which occur while calling __hash__()
and
__eq__()
methods will get suppressed.
To get error reporting use PyDict_GetItemWithError()
instead.
PyDict_GetItemWithError
(PyObject *p, PyObject *key)Return value: Borrowed reference.
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)Return value: Borrowed reference.
This is the same as PyDict_GetItem()
, but key is specified as a
const 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()
instead.
PyDict_SetDefault
(PyObject *p, PyObject *key, PyObject *defaultobj)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.
New in version 3.4.
PyDict_Items
(PyObject *p)Return value: New reference.
Return a PyListObject
containing all the items from the dictionary.
PyDict_Keys
(PyObject *p)Return value: New reference.
Return a PyListObject
containing all the keys from the dictionary.
PyDict_Values
(PyObject *p)Return value: New reference.
Return a PyListObject
containing all the values from the dictionary
p.
PyDict_Size
(PyObject *p)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. 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.
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);
}
PyDict_Merge
(PyObject *a, PyObject *b, int override)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.PyDict_Update
(PyObject *a, PyObject *b)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