Dictionary Objects¶
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PyTypeObject PyDict_Type¶
- This instance of - PyTypeObjectrepresents the Python dictionary type. This is the same object as- dictin 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. This function always succeeds. 
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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. This function always succeeds. 
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PyObject* PyDict_New()¶
- Return value: New reference.Return a new empty dictionary, or NULLon failure.
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PyObject* PyDictProxy_New(PyObject *mapping)¶
- Return value: New reference.Return a types.MappingProxyTypeobject 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 return- 0. On error, return- -1. This is equivalent to the Python expression- key 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 val into the dictionary p with a key of key. key must be hashable; if it isn’t, - TypeErrorwill be raised. Return- 0on success or- -1on failure. This function does not steal a reference to val.
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int PyDict_SetItemString(PyObject *p, const char *key, PyObject *val)¶
- Insert val into the dictionary p using key as a key. key should be a - const char*. The key object is created using- PyUnicode_FromString(key). Return- 0on success or- -1on failure. This function does not steal a reference to val.
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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, - TypeErroris raised. If key is not in the dictionary,- KeyErroris raised. Return- 0on success or- -1on 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. If key is not in the dictionary, - KeyErroris raised. Return- 0on success or- -1on 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 NULLif 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 usePyDict_GetItemWithError()instead.
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PyObject* PyDict_GetItemWithError(PyObject *p, PyObject *key)¶
- Return value: Borrowed reference.Variant of PyDict_GetItem()that does not suppress exceptions. ReturnNULLwith an exception set if an exception occurred. ReturnNULLwithout 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 aconst char*, rather than aPyObject*.Note that exceptions which occur while calling __hash__()and__eq__()methods and creating a temporary string object will get suppressed. To get error reporting usePyDict_GetItemWithError()instead.
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PyObject* 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. 
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PyObject* PyDict_Items(PyObject *p)¶
- Return value: New reference.Return a PyListObjectcontaining all the items from the dictionary.
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PyObject* PyDict_Keys(PyObject *p)¶
- Return value: New reference.Return a PyListObjectcontaining all the keys from the dictionary.
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PyObject* PyDict_Values(PyObject *p)¶
- Return value: New reference.Return a PyListObjectcontaining 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_treferred to by ppos must be initialized to- 0prior 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); } 
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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()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- 0on success or- -1if 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 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- 0on success or- -1if 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 - 0on success or- -1if 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