程式碼物件

程式碼物件是 CPython 實作的低階細節。每個程式碼物件都代表一段尚未綁定到函式的可執行程式碼。

type PyCodeObject

用於描述程式碼物件的 C 結構。此型別的欄位隨時可能變更。

PyTypeObject PyCode_Type

這是 PyTypeObject 的一個實例，代表 Python 的程式碼物件。

int PyCode_Check(PyObject *co)

如果 co 是程式碼物件，則回傳 true。此函式總會成功執行。

Py_ssize_t PyCode_GetNumFree(PyCodeObject *co)

回傳程式碼物件中 自由（閉包）變數的數量。

int PyUnstable_Code_GetFirstFree(PyCodeObject *co)

這是 不穩定 API，它可能在小版本發布中沒有任何警告地被變更。

回傳程式碼物件中第一個自由（閉包）變數的位置。

在 3.13 版的變更: Renamed from PyCode_GetFirstFree as part of 不穩定的 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)

這是 不穩定 API，它可能在小版本發布中沒有任何警告地被變更。

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.

在 3.11 版的變更: 新增 qualname 和 exceptiontable 參數。

在 3.12 版的變更: Renamed from PyCode_New as part of 不穩定的 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)

這是 不穩定 API，它可能在小版本發布中沒有任何警告地被變更。

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.

在 3.8 版被加入: 名為 PyCode_NewWithPosOnlyArgs

在 3.11 版的變更: 新增 qualname 和 exceptiontable 參數。

在 3.12 版的變更: 重新命名為 PyUnstable_Code_NewWithPosOnlyArgs。舊的名稱已被棄用，但在簽名再次變更前仍可使用。

PyCodeObject *PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)

回傳值：新的參照。

Return a new empty code object with the specified filename, function name, and first line number. The resulting code object will raise an Exception if executed.

int PyCode_Addr2Line(PyCodeObject *co, int byte_offset)

Return the line number of the instruction that occurs on or before byte_offset and ends after it. If you just need the line number of a frame, use PyFrame_GetLineNumber() instead.

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)

Sets the passed int pointers to the source code line and column numbers for the instruction at byte_offset. Sets the value to 0 when information is not available for any particular element.

如果函式成功則回傳 1，否則回傳 0。

在 3.11 版被加入.

PyObject *PyCode_GetCode(PyCodeObject *co)

Equivalent to the Python code getattr(co, 'co_code'). Returns a strong reference to a PyBytesObject representing the bytecode in a code object. On error, NULL is returned and an exception is raised.

This PyBytesObject may be created on-demand by the interpreter and does not necessarily represent the bytecode actually executed by CPython. The primary use case for this function is debuggers and profilers.

在 3.11 版被加入.

PyObject *PyCode_GetVarnames(PyCodeObject *co)

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

在 3.11 版被加入.

PyObject *PyCode_GetCellvars(PyCodeObject *co)

Equivalent to the Python code getattr(co, 'co_cellvars'). Returns a new reference to a PyTupleObject containing the names of the local variables that are referenced by nested functions. On error, NULL is returned and an exception is raised.

在 3.11 版被加入.

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.

在 3.11 版被加入.

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.

在 3.12 版被加入.

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.)

在 3.12 版被加入.

type PyCodeEvent

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

在 3.12 版被加入.

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.

在 3.12 版被加入.

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

This is a soft deprecated function that does nothing.

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

在 3.10 版的變更: This function now does nothing.

程式碼物件旗標

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.

旗標	意義
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	無效果（__future__.division）
CO_FUTURE_ABSOLUTE_IMPORT	無效果（__future__.absolute_import）
CO_FUTURE_WITH_STATEMENT	無效果（__future__.with_statement）
CO_FUTURE_PRINT_FUNCTION	無效果（__future__.print_function）
CO_FUTURE_UNICODE_LITERALS	無效果（__future__.unicode_literals）
CO_FUTURE_GENERATOR_STOP	無效果（__future__.generator_stop）
CO_FUTURE_ANNOTATIONS	__future__.annotations

額外資訊

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)

這是 不穩定 API，它可能在小版本發布中沒有任何警告地被變更。

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.

在 3.6 版被加入: 名為 _PyEval_RequestCodeExtraIndex

在 3.12 版的變更: 重新命名為 PyUnstable_Eval_RequestCodeExtraIndex。舊的私有名稱已被棄用，但在 API 變更前仍可使用。

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

這是 不穩定 API，它可能在小版本發布中沒有任何警告地被變更。

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.

在 3.6 版被加入: 名為 _PyCode_GetExtra

在 3.12 版的變更: 重新命名為 PyUnstable_Code_GetExtra。舊的私有名稱已被棄用，但在 API 變更前仍可使用。

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

這是 不穩定 API，它可能在小版本發布中沒有任何警告地被變更。

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

在 3.6 版被加入: 名為 _PyCode_SetExtra

在 3.12 版的變更: 重新命名為 PyUnstable_Code_SetExtra。舊的私有名稱已被棄用，但在 API 變更前仍可使用。