Objetos código#

Los objetos código son un detalle de bajo nivel de la implementación de CPython. Cada uno representa un fragmento de código ejecutable que aún no se ha vinculado a una función.

type PyCodeObject

La estructura en C de los objetos utilizados para describir objetos código. Los campos de este tipo están sujetos a cambios en cualquier momento.

PyTypeObject PyCode_Type

This is an instance of "PyTypeObject" representing the Python code object.

int PyCode_Check(PyObject *co)

Return true if co is a code object. This function always succeeds.

Py_ssize_t PyCode_GetNumFree(PyCodeObject *co)

Return the number of free (closure) variables in a code object.

int PyUnstable_Code_GetFirstFree(PyCodeObject *co)

This is Unstable API. It may change without warning in minor releases.

Return the position of the first free (closure) variable in a code object.

Distinto en la versión 3.13: Renamed from "PyCode_GetFirstFree" as part of Unstable C API. The old name is deprecated, but will remain available until the signature changes again.

PyCodeObject PyUnstable_Code_New(int argcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject code, PyObject consts, PyObject names, PyObject varnames, PyObject freevars, PyObject cellvars, PyObject filename, PyObject name, PyObject qualname, int firstlineno, PyObject linetable, PyObject exceptiontable)

This is Unstable API. It may change without warning in minor releases.

Return a new code object. If you need a dummy code object to create a frame, use "PyCode_NewEmpty()" instead.

Since the definition of the bytecode changes often, calling "PyUnstable_Code_New()" directly can bind you to a precise Python version.

The many arguments of this function are inter-dependent in complex ways, meaning that subtle changes to values are likely to result in incorrect execution or VM crashes. Use this function only with extreme care.

Distinto en la versión 3.11: Added "qualname" and "exceptiontable" parameters.

Distinto en la versión 3.12: Renamed from "PyCode_New" as part of Unstable C API. The old name is deprecated, but will remain available until the signature changes again.

PyCodeObject PyUnstable_Code_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount, int nlocals, int stacksize, int flags, PyObject code, PyObject consts, PyObject names, PyObject varnames, PyObject freevars, PyObject cellvars, PyObject filename, PyObject name, PyObject qualname, int firstlineno, PyObject linetable, PyObject exceptiontable)

This is Unstable API. It may change without warning in minor releases.

Similar to "PyUnstable_Code_New()", but with an extra "posonlyargcount" for positional-only arguments. The same caveats that apply to "PyUnstable_Code_New" also apply to this function.

Added in version 3.8: as "PyCode_NewWithPosOnlyArgs"

Distinto en la versión 3.11: Added "qualname" and "exceptiontable" parameters.

Distinto en la versión 3.12: Renamed to "PyUnstable_Code_NewWithPosOnlyArgs". The old name is deprecated, but will remain available until the signature changes again.

PyCodeObject PyCode_NewEmpty(const char filename, const char funcname, int firstlineno) Return value: New reference.*

Retorna un nuevo objeto de código vacío con el nombre de archivo especificado, el nombre de la función y el número de la primera línea. Si el objeto código resultante es ejecutado, lanzará una "Exception".

int PyCode_Addr2Line(PyCodeObject *co, int byte_offset)

Retorna el número de línea de la instrucción que se produce en o antes de "byte_offset" y finaliza después. Si solo necesita el número de línea de un marco, use "PyFrame_GetLineNumber()" en su lugar.

For efficiently iterating over the line numbers in a code object, use the API described in PEP 626.

int PyCode_Addr2Location(PyObject co, int byte_offset, int start_line, int start_column, int end_line, int *end_column)

Establece los punteros "int" pasados en los números de línea y columna del código fuente para las instrucciones en "byte_offset". Establece el valor en "0" cuando la información no está disponible para algún elemento en particular.

Retorna "1" si la función fue exitosa y "0" de lo contrario.

Added in version 3.11.

PyObject PyCode_GetCode(PyCodeObject co)

Equivalente al código Python "getattr(co, 'co_code')". Retorna una referencia fuerte a un "PyBytesObject" representando el bytecode en un objecto código. En caso de error se retorna "NULL" y se lanza una excepción.

Este "PyBytesObject" puede ser creado a pedido del intérprete y no necesariamente representa el bytecode que es realmente ejecutado por CPython. Los casos de uso principales para esta función son depuradores y perfiladores.

Added in version 3.11.

PyObject PyCode_GetVarnames(PyCodeObject co)

Equivalente al código Python "getattr(co, 'co_varnames')". Retorna una nueva referencia a un "PyTupleObject" que contiene los nombres de las variables locales. En caso de error, retorna "NULL" y lanza una excepción.

Added in version 3.11.

PyObject PyCode_GetCellvars(PyCodeObject co)

Equivalente al código Python "getattr(co, 'co_cellvars')". Retorna una nueva referencia a un "PyTupleObject" que contiene los nombres de las variables locales referenciadas por funciones anidadas. En caso de error, retorna "NULL" y lanza una excepción.

Added in version 3.11.

PyObject PyCode_GetFreevars(PyCodeObject co)

Equivalent to the Python code "getattr(co, 'co_freevars')". Returns a new reference to a "PyTupleObject" containing the names of the free (closure) variables. On error, "NULL" is returned and an exception is raised.

Added in version 3.11.

int PyCode_AddWatcher(PyCode_WatchCallback callback)

Register callback as a code object watcher for the current interpreter. Return an ID which may be passed to "PyCode_ClearWatcher()". In case of error (e.g. no more watcher IDs available), return "-1" and set an exception.

Added in version 3.12.

int PyCode_ClearWatcher(int watcher_id)

Clear watcher identified by watcher_id previously returned from "PyCode_AddWatcher()" for the current interpreter. Return "0" on success, or "-1" and set an exception on error (e.g. if the given watcher_id was never registered.)

Added in version 3.12.

type PyCodeEvent

Enumeration of possible code object watcher events: - "PY_CODE_EVENT_CREATE" - "PY_CODE_EVENT_DESTROY"

Added in version 3.12.

typedef int (PyCode_WatchCallback)(PyCodeEvent event, PyCodeObject co)

Type of a code object watcher callback function.

If event is "PY_CODE_EVENT_CREATE", then the callback is invoked after co has been fully initialized. Otherwise, the callback is invoked before the destruction of co takes place, so the prior state of co can be inspected.

If event is "PY_CODE_EVENT_DESTROY", taking a reference in the callback to the about-to-be-destroyed code object 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.

Users of this API should not rely on internal runtime implementation details. Such details may include, but are not limited to, the exact order and timing of creation and destruction of code objects. While changes in these details may result in differences observable by watchers (including whether a callback is invoked or not), it does not change the semantics of the Python code being executed.

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.

PyObject PyCode_Optimize(PyObject code, PyObject consts, PyObject names, PyObject *lnotab_obj)

This is a function that does nothing.

Prior to Python 3.10, this function would perform basic optimizations to a code object.

Distinto en la versión 3.10: This function now does nothing.

Soft deprecated since version 3.13.

Code Object Flags#

Code objects contain a bit-field of flags, which can be retrieved as the "co_flags" Python attribute (for example using "PyObject_GetAttrString()"), and set using a flags argument to "PyUnstable_Code_New()" and similar functions.

Flags whose names start with "CO_FUTURE_" correspond to features normally selectable by future statements. These flags can be used in "PyCompilerFlags.cf_flags". Note that many "CO_FUTURE_" flags are mandatory in current versions of Python, and setting them has no effect.

The following flags are available. For their meaning, see the linked documentation of their Python equivalents.

+----------------------------------------------------+----------------------------------------------------+ | Flag | Meaning | |====================================================|====================================================|

| CO_OPTIMIZED | "inspect.CO_OPTIMIZED" |#

| CO_NEWLOCALS | "inspect.CO_NEWLOCALS" |#

| CO_VARARGS | "inspect.CO_VARARGS" |#

| CO_VARKEYWORDS | "inspect.CO_VARKEYWORDS" |#

| CO_NESTED | "inspect.CO_NESTED" |#

| CO_GENERATOR | "inspect.CO_GENERATOR" |#

| CO_COROUTINE | "inspect.CO_COROUTINE" |#

| CO_ITERABLE_COROUTINE | "inspect.CO_ITERABLE_COROUTINE" |#

| CO_ASYNC_GENERATOR | "inspect.CO_ASYNC_GENERATOR" |#

| CO_HAS_DOCSTRING | "inspect.CO_HAS_DOCSTRING" |#

| CO_METHOD | "inspect.CO_METHOD" |#

| CO_FUTURE_DIVISION | no effect ("future.division") |#

| CO_FUTURE_ABSOLUTE_IMPORT | no effect ("future.absolute_import") |#

| CO_FUTURE_WITH_STATEMENT | no effect ("future.with_statement") |#

| CO_FUTURE_PRINT_FUNCTION | no effect ("future.print_function") |#

| CO_FUTURE_UNICODE_LITERALS | no effect ("future.unicode_literals") |#

| CO_FUTURE_GENERATOR_STOP | no effect ("future.generator_stop") |#

| CO_FUTURE_ANNOTATIONS | "future.annotations" |#

Extra information#

To support low-level extensions to frame evaluation, such as external just-in-time compilers, it is possible to attach arbitrary extra data to code objects.

These functions are part of the unstable C API tier: this functionality is a CPython implementation detail, and the API may change without deprecation warnings.

Py_ssize_t PyUnstable_Eval_RequestCodeExtraIndex(freefunc free)

This is Unstable API. It may change without warning in minor releases.

Return a new opaque index value used to adding data to code objects.

You generally call this function once (per interpreter) and use the result with "PyCode_GetExtra" and "PyCode_SetExtra" to manipulate data on individual code objects.

If free is not "NULL": when a code object is deallocated, free will be called on non-"NULL" data stored under the new index. Use "Py_DecRef()" when storing "PyObject".

Added in version 3.6: as "_PyEval_RequestCodeExtraIndex"

Distinto en la versión 3.12: Renamed to "PyUnstable_Eval_RequestCodeExtraIndex". The old private name is deprecated, but will be available until the API changes.

int PyUnstable_Code_GetExtra(PyObject code, Py_ssize_t index, void *extra)

This is Unstable API. It may change without warning in minor releases.

Set extra to the extra data stored under the given index. Return 0 on success. Set an exception and return -1 on failure.

If no data was set under the index, set extra to "NULL" and return 0 without setting an exception.

Added in version 3.6: as "_PyCode_GetExtra"

Distinto en la versión 3.12: Renamed to "PyUnstable_Code_GetExtra". The old private name is deprecated, but will be available until the API changes.

int PyUnstable_Code_SetExtra(PyObject code, Py_ssize_t index, void extra)

This is Unstable API. It may change without warning in minor releases.

Set the extra data stored under the given index to extra. Return 0 on success. Set an exception and return -1 on failure.

Added in version 3.6: as "_PyCode_SetExtra"

Distinto en la versión 3.12: Renamed to "PyUnstable_Code_SetExtra". The old private name is deprecated, but will be available until the API changes.