Objetos diccionario

type PyDictObject

Este subtipo de PyObject representa un objeto diccionario de Python.

PyTypeObject PyDict_Type
Part of the Stable ABI.

Esta instancia de PyTypeObject representa el tipo diccionario de Python. Este es el mismo objeto que dict en la capa de Python.

int PyDict_Check(PyObject *p)

Retorna verdadero si p es un objeto dict o una instancia de un subtipo del tipo dict. Esta función siempre finaliza con éxito.

int PyDict_CheckExact(PyObject *p)

Retorna verdadero si p es un objeto dict, pero no una instancia de un subtipo del tipo dict. Esta función siempre finaliza con éxito.

PyObject *PyDict_New()
Return value: New reference. Part of the Stable ABI.

Retorna un nuevo diccionario vacío, o NULL en caso de falla.

PyObject *PyDictProxy_New(PyObject *mapping)
Return value: New reference. Part of the Stable ABI.

Retorna un objeto a types.MappingProxyType para una asignación que imponga un comportamiento de solo lectura. Esto normalmente se usa para crear una vista para evitar la modificación del diccionario para los tipos de clase no dinámicos.

void PyDict_Clear(PyObject *p)
Part of the Stable ABI.

Vacía un diccionario existente de todos los pares clave-valor (key-value).

int PyDict_Contains(PyObject *p, PyObject *key)
Part of the Stable ABI.

Determine si el diccionario p contiene key. Si un elemento en p coincide con la clave key, retorna 1; de lo contrario, retorna 0. En caso de error, retorna -1. Esto es equivalente a la expresión de Python key in p.

int PyDict_ContainsString(PyObject *p, const char *key)

This is the same as PyDict_Contains(), but key is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

Added in version 3.13.

PyObject *PyDict_Copy(PyObject *p)
Return value: New reference. Part of the Stable ABI.

Retorna un nuevo diccionario que contiene los mismos pares clave-valor (key-value) que p.

int PyDict_SetItem(PyObject *p, PyObject *key, PyObject *val)
Part of the Stable ABI.

Inserta val en el diccionario p con una clave key. key debe ser hashable; si no lo es, se lanzará TypeError. Retorna 0 en caso de éxito o -1 en caso de error. Esta función no roba una referencia a val.

int PyDict_SetItemString(PyObject *p, const char *key, PyObject *val)
Part of the Stable ABI.

This is the same as PyDict_SetItem(), but key is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

int PyDict_DelItem(PyObject *p, PyObject *key)
Part of the Stable ABI.

Remove the entry in dictionary p with key key. key must be hashable; if it isn’t, TypeError is raised. If key is not in the dictionary, KeyError is raised. Return 0 on success or -1 on failure.

int PyDict_DelItemString(PyObject *p, const char *key)
Part of the Stable ABI.

This is the same as PyDict_DelItem(), but key is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

int PyDict_GetItemRef(PyObject *p, PyObject *key, PyObject **result)
Part of the Stable ABI since version 3.13.

Return a new strong reference to the object from dictionary p which has a key key:

  • If the key is present, set *result to a new strong reference to the value and return 1.

  • If the key is missing, set *result to NULL and return 0.

  • On error, raise an exception and return -1.

Added in version 3.13.

See also the PyObject_GetItem() function.

PyObject *PyDict_GetItem(PyObject *p, PyObject *key)
Return value: Borrowed reference. Part of the Stable ABI.

Return a borrowed reference to the object from dictionary p which has a key key. Return NULL if the key key is missing without setting an exception.

Nota

Exceptions that occur while this calls __hash__() and __eq__() methods are silently ignored. Prefer the PyDict_GetItemWithError() function instead.

Distinto en la versión 3.10: Llamar a esta API sin retener el GIL había sido permitido por motivos históricos.Ya no está permitido.

PyObject *PyDict_GetItemWithError(PyObject *p, PyObject *key)
Return value: Borrowed reference. Part of the Stable ABI.

Variante de PyDict_GetItem() que no suprime las excepciones. Retorna NULL con una excepción establecida si se produjo una excepción. Retorna NULL sin una excepción establecida si la clave no estaba presente.

PyObject *PyDict_GetItemString(PyObject *p, const char *key)
Return value: Borrowed reference. Part of the Stable ABI.

This is the same as PyDict_GetItem(), but key is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

Nota

Exceptions that occur while this calls __hash__() and __eq__() methods or while creating the temporary str object are silently ignored. Prefer using the PyDict_GetItemWithError() function with your own PyUnicode_FromString() key instead.

int PyDict_GetItemStringRef(PyObject *p, const char *key, PyObject **result)
Part of the Stable ABI since version 3.13.

Similar than PyDict_GetItemRef(), but key is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

Added in version 3.13.

PyObject *PyDict_SetDefault(PyObject *p, PyObject *key, PyObject *defaultobj)
Return value: Borrowed reference.

Esto es lo mismo al nivel de Python dict.setdefault(). Si está presente, retorna el valor correspondiente a key del diccionario p. Si la clave no está en el dict, se inserta con el valor defaultobj y se retorna defaultobj. Esta función evalúa la función hash de key solo una vez, en lugar de evaluarla independientemente para la búsqueda y la inserción.

Added in version 3.4.

int PyDict_SetDefaultRef(PyObject *p, PyObject *key, PyObject *default_value, PyObject **result)

Inserts default_value into the dictionary p with a key of key if the key is not already present in the dictionary. If result is not NULL, then *result is set to a strong reference to either default_value, if the key was not present, or the existing value, if key was already present in the dictionary. Returns 1 if the key was present and default_value was not inserted, or 0 if the key was not present and default_value was inserted. On failure, returns -1, sets an exception, and sets *result to NULL.

For clarity: if you have a strong reference to default_value before calling this function, then after it returns, you hold a strong reference to both default_value and *result (if it’s not NULL). These may refer to the same object: in that case you hold two separate references to it.

Added in version 3.13.

int PyDict_Pop(PyObject *p, PyObject *key, PyObject **result)

Remove key from dictionary p and optionally return the removed value. Do not raise KeyError if the key missing.

  • If the key is present, set *result to a new reference to the removed value if result is not NULL, and return 1.

  • If the key is missing, set *result to NULL if result is not NULL, and return 0.

  • On error, raise an exception and return -1.

This is similar to dict.pop(), but without the default value and not raising KeyError if the key missing.

Added in version 3.13.

int PyDict_PopString(PyObject *p, const char *key, PyObject **result)

Similar to PyDict_Pop(), but key is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

Added in version 3.13.

PyObject *PyDict_Items(PyObject *p)
Return value: New reference. Part of the Stable ABI.

Retorna un PyListObject que contiene todos los elementos del diccionario.

PyObject *PyDict_Keys(PyObject *p)
Return value: New reference. Part of the Stable ABI.

Retorna un PyListObject que contiene todas las claves del diccionario.

PyObject *PyDict_Values(PyObject *p)
Return value: New reference. Part of the Stable ABI.

Retorna un PyListObject que contiene todos los valores del diccionario p.

Py_ssize_t PyDict_Size(PyObject *p)
Part of the Stable ABI.

Retorna el número de elementos en el diccionario. Esto es equivalente a len(p) en un diccionario.

int PyDict_Next(PyObject *p, Py_ssize_t *ppos, PyObject **pkey, PyObject **pvalue)
Part of the Stable ABI.

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.

Por ejemplo:

PyObject *key, *value;
Py_ssize_t pos = 0;

while (PyDict_Next(self->dict, &pos, &key, &value)) {
    /* do something interesting with the values... */
    ...
}

El diccionario p no debe mutarse durante la iteración. Es seguro modificar los valores de las claves a medida que recorre el diccionario, pero solo mientras el conjunto de claves no cambie. Por ejemplo:

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);
}
int PyDict_Merge(PyObject *a, PyObject *b, int override)
Part of the Stable ABI.

Itera sobre el objeto de mapeo b agregando pares clave-valor al diccionario a. b puede ser un diccionario o cualquier objeto que soporte PyMapping_Keys() y PyObject_GetItem(). Si override es verdadero, los pares existentes en a se reemplazarán si se encuentra una clave coincidente en b, de lo contrario, los pares solo se agregarán si no hay una clave coincidente en a. Retorna 0 en caso de éxito o -1 si se lanza una excepción.

int PyDict_Update(PyObject *a, PyObject *b)
Part of the Stable ABI.

Esto es lo mismo que PyDict_Merge(a, b, 1) en C, y es similar a a.update(b) en Python excepto que PyDict_Update() no vuelve a la iteración sobre una secuencia de pares de valores clave si el segundo argumento no tiene el atributo «claves». Retorna 0 en caso de éxito o -1 si se produjo una excepción.

int PyDict_MergeFromSeq2(PyObject *a, PyObject *seq2, int override)
Part of the Stable ABI.

Actualiza o combina en el diccionario a, desde los pares clave-valor en seq2. seq2 debe ser un objeto iterable que produzca objetos iterables de longitud 2, vistos como pares clave-valor. En el caso de claves duplicadas, el último gana si override es verdadero, de lo contrario, el primero gana. Retorna 0 en caso de éxito o -1 si se produjo una excepción. El equivalente en Python (excepto el valor de retorno)

def PyDict_MergeFromSeq2(a, seq2, override):
    for key, value in seq2:
        if override or key not in a:
            a[key] = value
int PyDict_AddWatcher(PyDict_WatchCallback callback)

Register callback as a dictionary watcher. Return a non-negative integer id which must be passed to future calls to PyDict_Watch(). In case of error (e.g. no more watcher IDs available), return -1 and set an exception.

Added in version 3.12.

int PyDict_ClearWatcher(int watcher_id)

Clear watcher identified by watcher_id previously returned from PyDict_AddWatcher(). Return 0 on success, -1 on error (e.g. if the given watcher_id was never registered.)

Added in version 3.12.

int PyDict_Watch(int watcher_id, PyObject *dict)

Mark dictionary dict as watched. The callback granted watcher_id by PyDict_AddWatcher() will be called when dict is modified or deallocated. Return 0 on success or -1 on error.

Added in version 3.12.

int PyDict_Unwatch(int watcher_id, PyObject *dict)

Mark dictionary dict as no longer watched. The callback granted watcher_id by PyDict_AddWatcher() will no longer be called when dict is modified or deallocated. The dict must previously have been watched by this watcher. Return 0 on success or -1 on error.

Added in version 3.12.

type PyDict_WatchEvent

Enumeration of possible dictionary watcher events: PyDict_EVENT_ADDED, PyDict_EVENT_MODIFIED, PyDict_EVENT_DELETED, PyDict_EVENT_CLONED, PyDict_EVENT_CLEARED, or PyDict_EVENT_DEALLOCATED.

Added in version 3.12.

typedef int (*PyDict_WatchCallback)(PyDict_WatchEvent event, PyObject *dict, PyObject *key, PyObject *new_value)

Type of a dict watcher callback function.

If event is PyDict_EVENT_CLEARED or PyDict_EVENT_DEALLOCATED, both key and new_value will be NULL. If event is PyDict_EVENT_ADDED or PyDict_EVENT_MODIFIED, new_value will be the new value for key. If event is PyDict_EVENT_DELETED, key is being deleted from the dictionary and new_value will be NULL.

PyDict_EVENT_CLONED occurs when dict was previously empty and another dict is merged into it. To maintain efficiency of this operation, per-key PyDict_EVENT_ADDED events are not issued in this case; instead a single PyDict_EVENT_CLONED is issued, and key will be the source dictionary.

The callback may inspect but must not modify dict; doing so could have unpredictable effects, including infinite recursion. Do not trigger Python code execution in the callback, as it could modify the dict as a side effect.

If event is PyDict_EVENT_DEALLOCATED, taking a new reference in the callback to the about-to-be-destroyed dictionary will resurrect it and prevent it from being freed at this time. When the resurrected object is destroyed later, any watcher callbacks active at that time will be called again.

Callbacks occur before the notified modification to dict takes place, so the prior state of dict can be inspected.

If the callback sets an exception, it must return -1; this exception will be printed as an unraisable exception using PyErr_WriteUnraisable(). Otherwise it should return 0.

There may already be a pending exception set on entry to the callback. In this case, the callback should return 0 with the same exception still set. This means the callback may not call any other API that can set an exception unless it saves and clears the exception state first, and restores it before returning.

Added in version 3.12.