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) * Thread safety: Atomic.

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) * Thread safety: Atomic.

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. Thread safety: Atomic.*

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.

PyTypeObject PyDictProxy_Type * Part of the Stable ABI.*

The type object for mapping proxy objects created by "PyDictProxy_New()" and for the read-only "dict" attribute of many built-in types. A "PyDictProxy_Type" instance provides a dynamic, read-only view of an underlying dictionary: changes to the underlying dictionary are reflected in the proxy, but the proxy itself does not support mutation operations. This corresponds to "types.MappingProxyType" in Python.

void PyDict_Clear(PyObject p) * Part of the Stable ABI. Thread safety: Atomic.

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

int PyDict_Contains(PyObject p, PyObject key) * Part of the Stable ABI.* Thread safety: Safe for concurrent use on the same object.

Determine if dictionary p contains key. If an item in p matches key, return "1", otherwise return "0". On error, return "-1". This is equivalent to the Python expression "key in p".

Nota:

 The operation is atomic on *free threading* when *key* is "str",
 "int", "float", "bool" or "bytes".

int PyDict_ContainsString(PyObject p, const char key) * Thread safety: Atomic.*

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. Thread safety: Atomic.

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. Thread safety: Safe for concurrent use on the same object.

Insert val into the dictionary p with a key of key. key must be hashable; if it isn't, "TypeError" will be raised. Return "0" on success or "-1" on failure. This function does not "steal" a reference to val.

Nota:

 The operation is atomic on *free threading* when *key* is "str",
 "int", "float", "bool" or "bytes".

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

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.* Thread safety: Safe for concurrent use on the same object.

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.

Nota:

 The operation is atomic on *free threading* when *key* is "str",
 "int", "float", "bool" or "bytes".

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

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. Thread safety: Safe for concurrent use on the same object.*

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, set *result to "NULL" and return "-1".

Nota:

 The operation is atomic on *free threading* when *key* is "str",
 "int", "float", "bool" or "bytes".

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. Thread safety: Safe to call from multiple threads with external synchronization only.*

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.

Nota:

 In the *free-threaded build*, the returned *borrowed reference*
 may become invalid if another thread modifies the dictionary
 concurrently. Prefer "PyDict_GetItemRef()", which returns a
 *strong reference*.

Distinto en la versión 3.10: Calling this API without an attached thread state had been allowed for historical reason. It is no longer allowed.

PyObject PyDict_GetItemWithError(PyObject p, PyObject key) Return value: Borrowed reference. Part of the Stable ABI. Thread safety: Safe to call from multiple threads with external synchronization only.*

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.

Nota:

 In the *free-threaded build*, the returned *borrowed reference*
 may become invalid if another thread modifies the dictionary
 concurrently. Prefer "PyDict_GetItemRef()", which returns a
 *strong reference*.

PyObject PyDict_GetItemString(PyObject p, const char key) Return value: Borrowed reference. Part of the Stable ABI. Thread safety: Safe to call from multiple threads with external synchronization only.*

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.

Nota:

 In the *free-threaded build*, the returned *borrowed reference*
 may become invalid if another thread modifies the dictionary
 concurrently. Prefer "PyDict_GetItemStringRef()", which returns a
 *strong reference*.

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

Similar to "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. Thread safety: Safe to call from multiple threads with external synchronization only.

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.

Nota:

 In the *free-threaded build*, the returned *borrowed reference*
 may become invalid if another thread modifies the dictionary
 concurrently. Prefer "PyDict_SetDefaultRef()", which returns a
 *strong reference*.

int PyDict_SetDefaultRef(PyObject p, PyObject key, PyObject default_value, PyObject result) * Thread safety: Safe for concurrent use on the same object.

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.

Nota:

 The operation is atomic on *free threading* when *key* is "str",
 "int", "float", "bool" or "bytes".

Added in version 3.13.

int PyDict_Pop(PyObject p, PyObject key, PyObject *result) * Thread safety: Safe for concurrent use on the same object.

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

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

Nota:

 The operation is atomic on *free threading* when *key* is "str",
 "int", "float", "bool" or "bytes".

Added in version 3.13.

int PyDict_PopString(PyObject p, const char key, PyObject *result) * Thread safety: Atomic.

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. Thread safety: Atomic.

Retorna un "PyListObject" que contiene todos los elementos del diccionario.

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

Retorna un "PyListObject" que contiene todas las claves del diccionario.

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

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

Py_ssize_t PyDict_Size(PyObject p) * Part of the Stable ABI. Thread safety: Atomic.

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

Py_ssize_t PyDict_GET_SIZE(PyObject p) * Thread safety: Atomic.

Similar to "PyDict_Size()", but without error checking.

int PyDict_Next(PyObject p, Py_ssize_t ppos, PyObject pkey, PyObject pvalue) * Part of the Stable ABI.* Thread safety: Safe to call from multiple threads with external synchronization only.

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);
  }

The function is not thread-safe in the free-threaded build without external synchronization. You can use "Py_BEGIN_CRITICAL_SECTION" to lock the dictionary while iterating over it:

  Py_BEGIN_CRITICAL_SECTION(self->dict);
  while (PyDict_Next(self->dict, &pos, &key, &value)) {
      ...
  }
  Py_END_CRITICAL_SECTION();

Nota:

 On the free-threaded build, this function can be used safely
 inside a critical section. However, the references returned for
 *pkey* and *pvalue* are *borrowed* and are only valid while the
 critical section is held. If you need to use these objects
 outside the critical section or when the critical section can be
 suspended, create a *strong reference* (for example, using
 "Py_NewRef()").

int PyDict_Merge(PyObject a, PyObject b, int override) * Part of the Stable ABI.* Thread safety: Safe for concurrent use on the same object.

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.

Nota:

 In the *free-threaded build*, when *b* is a "dict" (with the
 standard iterator), both *a* and *b* are locked for the duration
 of the operation. When *b* is a non-dict mapping, only *a* is
 locked; *b* may be concurrently modified by another thread.

int PyDict_Update(PyObject a, PyObject b) * Part of the Stable ABI.* Thread safety: Safe for concurrent use on the same object.

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.

Nota:

 In the *free-threaded build*, when *b* is a "dict" (with the
 standard iterator), both *a* and *b* are locked for the duration
 of the operation. When *b* is a non-dict mapping, only *a* is
 locked; *b* may be concurrently modified by another thread.

int PyDict_MergeFromSeq2(PyObject a, PyObject seq2, int override) * Part of the Stable ABI.* Thread safety: Safe for concurrent use on the same object.

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

Nota:

 In the *free-threaded* build, only *a* is locked. The iteration
 over *seq2* is not synchronized; *seq2* may be concurrently
 modified by another thread.

int PyDict_AddWatcher(PyDict_WatchCallback callback) * Thread safety: Safe to call from multiple threads with external synchronization only.*

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.

Nota:

 This function is not internally synchronized. In the *free-
 threaded* build, callers should ensure no concurrent calls to
 "PyDict_AddWatcher()" or "PyDict_ClearWatcher()" are in progress.

Added in version 3.12.

int PyDict_ClearWatcher(int watcher_id) * Thread safety: Safe to call from multiple threads with external synchronization only.*

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.)

Nota:

 This function is not internally synchronized. In the *free-
 threaded* build, callers should ensure no concurrent calls to
 "PyDict_AddWatcher()" or "PyDict_ClearWatcher()" are in progress.

Added in version 3.12.

int PyDict_Watch(int watcher_id, PyObject dict) * Thread safety: Safe to call without external synchronization on distinct objects.

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) * Thread safety: Safe to call without external synchronization on distinct objects.

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.

Dictionary View Objects#

int PyDictViewSet_Check(PyObject *op)

Return true if op is a view of a set inside a dictionary. This is currently equivalent to PyDictKeys_Check(op) || PyDictItems_Check(op). This function always succeeds.

PyTypeObject PyDictKeys_Type * Part of the Stable ABI.*

Type object for a view of dictionary keys. In Python, this is the type of the object returned by "dict.keys()".

int PyDictKeys_Check(PyObject *op)

Return true if op is an instance of a dictionary keys view. This function always succeeds.

PyTypeObject PyDictValues_Type * Part of the Stable ABI.*

Type object for a view of dictionary values. In Python, this is the type of the object returned by "dict.values()".

int PyDictValues_Check(PyObject *op)

Return true if op is an instance of a dictionary values view. This function always succeeds.

PyTypeObject PyDictItems_Type * Part of the Stable ABI.*

Type object for a view of dictionary items. In Python, this is the type of the object returned by "dict.items()".

int PyDictItems_Check(PyObject *op)

Return true if op is an instance of a dictionary items view. This function always succeeds.

Ordered Dictionaries#

Python's C API provides interface for "collections.OrderedDict" from C. Since Python 3.7, dictionaries are ordered by default, so there is usually little need for these functions; prefer "PyDict*" where possible.

PyTypeObject PyODict_Type

Type object for ordered dictionaries. This is the same object as "collections.OrderedDict" in the Python layer.

int PyODict_Check(PyObject *od)

Return true if od is an ordered dictionary object or an instance of a subtype of the "OrderedDict" type. This function always succeeds.

int PyODict_CheckExact(PyObject *od)

Return true if od is an ordered dictionary object, but not an instance of a subtype of the "OrderedDict" type. This function always succeeds.

PyTypeObject PyODictKeys_Type

Analogous to "PyDictKeys_Type" for ordered dictionaries.

PyTypeObject PyODictValues_Type

Analogous to "PyDictValues_Type" for ordered dictionaries.

PyTypeObject PyODictItems_Type

Analogous to "PyDictItems_Type" for ordered dictionaries.

PyObject *PyODict_New(void)

Return a new empty ordered dictionary, or "NULL" on failure.

This is analogous to "PyDict_New()".

int PyODict_SetItem(PyObject od, PyObject key, PyObject *value)

Insert value into the ordered dictionary od with a key of key. Return "0" on success or "-1" with an exception set on failure.

This is analogous to "PyDict_SetItem()".

int PyODict_DelItem(PyObject od, PyObject key)

Remove the entry in the ordered dictionary od with key key. Return "0" on success or "-1" with an exception set on failure.

This is analogous to "PyDict_DelItem()".

These are soft deprecated aliases to "PyDict" APIs:

+----------------------------------------------------+----------------------------------------------------+ | "PyODict" | "PyDict" | |====================================================|====================================================|

| PyODict_GetItem(od, key) | "PyDict_GetItem()" |#

| PyODict_GetItemWithError(od, key) | "PyDict_GetItemWithError()" |#

| PyODict_GetItemString(od, key) | "PyDict_GetItemString()" |#

| PyODict_Contains(od, key) | "PyDict_Contains()" |#

| PyODict_Size(od) | "PyDict_Size()" |#

| PyODict_SIZE(od) | "PyDict_GET_SIZE()" |#