# 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`.

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*.

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

  Retorna el objeto del diccionario p que tiene una clave key. Retorna `NULL` si la clave key no está presente, pero sin lanzar una excepción.

  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.

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.

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.