PYTHONCAPI\_COMPAT(1) pythoncapi\_compat PYTHONCAPI\_COMPAT(1) # [NAME](#NAME) pythoncapi\_compat - pythoncapi\_compat The **pythoncapi-compat** project can be used to write a C or C++ extension supporting a wide range of Python versions with a single code base. It is made of the **pythoncapi\_compat.h** header file. - Homepage: GitHub pythoncapi-compat project <https://github.com/python/pythoncapi-compat>. - Documentation <https://pythoncapi-compat.readthedocs.io/en/latest/> Documentation: # [PYTHONCAPI\_COMPAT.H API](#PYTHONCAPI_COMPAT.H_API) The **pythoncapi\_compat.h** header file provides implementations of around 150 recent functions for old Python versions. Supported Python versions: - Python 3.6 - 3.16 - PyPy 3.6 - 3.12 The limited C API is only supported on CPython. A C11 subset (without optional features) is required, like **static inline** functions: see PEP 7 <https://www.python.org/dev/peps/pep-0007/>. C++03 and C++11 are supported on Python 3.6 and newer. Private functions (name starting with **\_Py**) are not supported. Latest version of the header file: pythoncapi\_compat.h <https://raw.githubusercontent.com/python/pythoncapi-compat/main/pythoncapi\_compat.h>. ## [Python 3.15](#Python_3.15) [**PyBytesWriter \*PyBytesWriter\_Create(Py\_ssize\_t size)**](#PyBytesWriter) [**void \*PyBytesWriter\_GetData(PyBytesWriter \*writer)**](#void) [**Py\_ssize\_t PyBytesWriter\_GetSize(PyBytesWriter \*writer)**](#Py_ssize_t) **PyObject \*PyBytesWriter\_FinishWithSize(PyBytesWriter \*writer, Py\_ssize\_t size)** **PyObject \*PyBytesWriter\_Finish(PyBytesWriter \*writer)** **PyObject \*PyBytesWriter\_FinishWithPointer(PyBytesWriter \*writer, void \*buf)** [**void PyBytesWriter\_Discard(PyBytesWriter \*writer)**](#void~2) [**int PyBytesWriter\_Resize(PyBytesWriter \*writer, Py\_ssize\_t size)**](#int) [**int PyBytesWriter\_Grow(PyBytesWriter \*writer, Py\_ssize\_t size)**](#int~2) [**void \*PyBytesWriter\_GrowAndUpdatePointer(PyBytesWriter \*writer, Py\_ssize\_t size, void \*buf)**](#void~3) [**int PyBytesWriter\_WriteBytes(PyBytesWriter \*writer, const void \*bytes, Py\_ssize\_t size)**](#int~3) [**int PyBytesWriter\_Format(PyBytesWriter \*writer, const char \*format, ...)**](#int~4) See PyBytesWriter documentation <https://docs.python.org/dev/c-api/bytes.html#pybyteswriter>. Not available on the limited C API. **PyObject \*PySys\_GetAttr(const char \*name)** See PySys\_GetAttr() documentation <https://docs.python.org/dev/c-api/sys.html#c.PySys\_GetAttr>. **PyObject \*PySys\_GetAttrString(const char \*name)** See PySys\_GetAttrString() documentation <https://docs.python.org/dev/c-api/sys.html#c.PySys\_GetAttrString>. **PyObject \*PySys\_GetOptionalAttr(const char \*name)** See PySys\_GetOptionalAttr() documentation <https://docs.python.org/dev/c-api/sys.html#c.PySys\_GetOptionalAttr>. **PyObject \*PySys\_GetOptionalAttrString(const char \*name)** See PySys\_GetOptionalAttrString() documentation <https://docs.python.org/dev/c-api/sys.html#c.PySys\_GetOptionalAttrString>. **PyObject \*PyTuple\_FromArray(PyObject \*const \*array, Py\_ssize\_t size)** See PyTuple\_FromArray() documentation <https://docs.python.org/dev/c-api/tuple.html#c.PyTuple\_FromArray>. [**Py\_hash\_t PyUnstable\_Unicode\_GET\_CACHED\_HASH(PyObject \*op)**](#Py_hash_t) See PyUnstable\_Unicode\_GET\_CACHED\_HASH() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnstable\_Unicode\_GET\_CACHED\_HASH>. On PyPy, always returns **-1**. Not available on the limited C API. [**int PyUnstable\_SetImmortal(PyObject \*op)**](#int~5) See PyUnstable\_SetImmortal() documentation <https://docs.python.org/dev/c-api/object.html#c.PyUnstable\_SetImmortal>. Availability: Python 3.13 and newer. Not available on PyPy, and not on the limited C API. Not supported: - **PyABIInfo\_Check()** - **PyAnyDict\_Check()** - **PyAnyDict\_CheckExact()** - **PyArg\_ParseArray()** - **PyArg\_ParseArrayAndKeywords()** - **PyFrozenDict\_Check()** - **PyFrozenDict\_CheckExact()** - **PyFrozenDict\_New()** - **PyImport\_CreateModuleFromInitfunc()** - **PyModule\_FromSlotsAndSpec()** - **PyModule\_GetState\_DuringGC()** - **PyModule\_GetToken\_DuringGC()** - **PyObject\_CallFinalizerFromDealloc()** - **PyObject\_Dump()** - **PyObject\_GetItemData\_DuringGC()** - **PyObject\_GetTypeData\_DuringGC()** - **PyType\_FromSlots()** - **PyType\_GetBaseByToken\_DuringGC()** - **PyType\_GetModuleByToken\_DuringGC()** - **PyType\_GetModuleState\_DuringGC()** - **PyType\_GetModule\_DuringGC()** - **PyUnstable\_DumpTraceback()** - **PyUnstable\_DumpTracebackThreads()** - **PyUnstable\_ThreadState\_ResetStackProtection()** - **PyUnstable\_ThreadState\_SetStackProtection()** ## [Python 3.14](#Python_3.14) [**struct PyLongLayout**](#struct) See PyLongLayout documentation <https://docs.python.org/dev/c-api/long.html#c.PyLongLayout>. Not available on the limited C API. [**const PyLongLayout <#c.PyLongLayout> \*PyLong\_GetNativeLayout(void)**](#const) See PyLong\_GetNativeLayout() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_GetNativeLayout>. Not available on the limited C API. [**struct PyLongExport**](#struct~2) See PyLongExport documentation <https://docs.python.org/dev/c-api/long.html#c.PyLongExport>. Not available on the limited C API. [**int PyLong\_Export(PyObject \*obj, PyLongExport <#c.PyLongExport> \*export\_long)**](#int~6) See PyLong\_Export() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_Export>. Not available on the limited C API. [**void PyLong\_FreeExport(PyLongExport <#c.PyLongExport> \*export\_long)**](#void~4) See PyLong\_FreeExport() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_FreeExport>. Not available on the limited C API. [**struct PyLongWriter**](#struct~3) See PyLongWriter documentation <https://docs.python.org/dev/c-api/long.html#c.PyLongWriter>. Not available on the limited C API. [**PyLongWriter <#c.PyLongWriter> \*PyLongWriter\_Create(int negative, Py\_ssize\_t ndigits, void \*\*digits)**](#PyLongWriter) See PyLongWriter\_Create() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLongWriter\_Create>. Not available on the limited C API. **PyObject \*PyLongWriter\_Finish(PyLongWriter <#c.PyLongWriter> \*writer)** See PyLongWriter\_Finish() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLongWriter\_Finish>. Not available on the limited C API. [**void PyLongWriter\_Discard(PyLongWriter <#c.PyLongWriter> \*writer)**](#void~5) See PyLongWriter\_Discard() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLongWriter\_Discard>. Not available on the limited C API. [**int PyLong\_IsPositive(PyObject \*obj)**](#int~7) See PyLong\_IsPositive() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_IsPositive>. [**int PyLong\_IsNegative(PyObject \*obj)**](#int~8) See PyLong\_IsNegative() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_IsNegative>. [**int PyLong\_IsZero(PyObject \*obj)**](#int~9) See PyLong\_IsZero() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_IsZero>. [**int PyLong\_GetSign(PyObject \*obj, int \*sign)**](#int~10) See PyLong\_GetSign() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_GetSign>. **PyObject \*PyIter\_NextItem(PyObject \*sep, PyObject \*iterable)** See PyIter\_NextItem() documentation <https://docs.python.org/dev/c-api/iter.html#c.PyIter\_NextItem>. Not available on limited C API 3.9 and older. **PyObject \*PyBytes\_Join(PyObject \*sep, PyObject \*iterable)** See PyBytes\_Join() documentation <https://docs.python.org/dev/c-api/bytes.html#c.PyBytes\_Join>. [**Py\_hash\_t Py\_HashBuffer(const void \*ptr, Py\_ssize\_t len)**](#Py_hash_t~2) See Py\_HashBuffer() documentation <https://docs.python.org/dev/c-api/hash.html#c.Py\_HashBuffer>. [**int PyUnicode\_Equal(PyObject \*str1, PyObject \*str2)**](#int~11) See PyUnicode\_Equal() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicode\_Equal>. [**PyUnicodeWriter \*PyUnicodeWriter\_Create(Py\_ssize\_t length)**](#PyUnicodeWriter) See PyUnicodeWriter\_Create() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_Create>. Not available on the limited C API. **PyObject \*PyUnicodeWriter\_Finish(PyUnicodeWriter \*writer)** See PyUnicodeWriter\_Finish() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_Finish>. Not available on the limited C API. [**void PyUnicodeWriter\_Discard(PyUnicodeWriter \*writer)**](#void~6) See PyUnicodeWriter\_Discard() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_Discard>. Not available on the limited C API. [**int PyUnicodeWriter\_WriteChar(PyUnicodeWriter \*writer, Py\_UCS4 ch)**](#int~12) See PyUnicodeWriter\_WriteChar() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_WriteChar>. Not available on the limited C API. [**int PyUnicodeWriter\_WriteUCS4(PyUnicodeWriter \*writer, const Py\_UCS4 \*ucs4, Py\_ssize\_t size)**](#int~13) See PyUnicodeWriter\_WriteUCS4() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_WriteUCS4>. Not available on the limited C API. [**int PyUnicodeWriter\_WriteUTF8(PyUnicodeWriter \*writer, const char \*str, Py\_ssize\_t size)**](#int~14) See PyUnicodeWriter\_WriteUTF8() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_WriteUTF8>. Not available on the limited C API. [**int PyUnicodeWriter\_WriteASCII(PyUnicodeWriter \*writer, const char \*str, Py\_ssize\_t size)**](#int~15) See PyUnicodeWriter\_WriteASCII() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_WriteASCII>. Not available on the limited C API. [**int PyUnicodeWriter\_WriteWideChar(PyUnicodeWriter \*writer, const wchar\_t \*str, Py\_ssize\_t size)**](#int~16) See PyUnicodeWriter\_WriteWideChar() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_WriteWideChar>. Not available on the limited C API. [**int PyUnicodeWriter\_WriteStr(PyUnicodeWriter \*writer, PyObject \*obj)**](#int~17) See PyUnicodeWriter\_WriteStr() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_WriteStr>. Not available on the limited C API. [**int PyUnicodeWriter\_WriteRepr(PyUnicodeWriter \*writer, PyObject \*obj)**](#int~18) See PyUnicodeWriter\_WriteRepr() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_WriteRepr>. Not available on the limited C API. [**int PyUnicodeWriter\_WriteSubstring(PyUnicodeWriter \*writer, PyObject \*str, Py\_ssize\_t start, Py\_ssize\_t end)**](#int~19) See PyUnicodeWriter\_WriteSubstring() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_WriteSubstring>. Not available on the limited C API. [**int PyUnicodeWriter\_Format(PyUnicodeWriter \*writer, const char \*format, ...)**](#int~20) See PyUnicodeWriter\_Format() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicodeWriter\_Format>. Not available on the limited C API. [**int PyLong\_AsInt32(PyObject \*obj, int32\_t \*pvalue)**](#int~21) See PyLong\_AsInt32() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_AsInt32>. [**int PyLong\_AsInt64(PyObject \*obj, int64\_t \*pvalue)**](#int~22) See PyLong\_AsInt64() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_AsInt64>. [**int PyLong\_AsUInt32(PyObject \*obj, uint32\_t \*pvalue)**](#int~23) See PyLong\_AsUInt32() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_AsUInt32>. [**int PyLong\_AsUInt64(PyObject \*obj, uint64\_t \*pvalue)**](#int~24) See PyLong\_AsUInt64() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_AsUInt64>. **PyObject \*PyLong\_FromInt32(int32\_t value)** See PyLong\_FromInt32() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_FromInt32>. **PyObject \*PyLong\_FromInt64(int64\_t value)** See PyLong\_FromInt64() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_FromInt64>. **PyObject \*PyLong\_FromUInt32(uint32\_t value)** See PyLong\_FromUInt32() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_FromUInt32>. **PyObject \*PyLong\_FromUInt64(uint64\_t value)** See PyLong\_FromUInt64() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_FromUInt64>. [**FILE \*Py\_fopen(PyObject \*path, const char \*mode)**](#FILE) See Py\_fopen() documentation <https://docs.python.org/dev/c-api/sys.html#c.Py\_fopen>. [**int Py\_fclose(FILE \*file)**](#int~25) See Py\_fclose() documentation <https://docs.python.org/dev/c-api/sys.html#c.Py\_fclose>. **PyObject \*PyConfig\_Get(const char \*name)** See PyConfig\_Get() documentation <https://docs.python.org/dev/c-api/init\_config.html#c.PyConfig\_Get>. Availability: Python 3.9 and newer. Not available on PyPy and not on the limited C API. [**int PyConfig\_GetInt(const char \*name, int \*value)**](#int~26) See PyConfig\_GetInt() documentation <https://docs.python.org/dev/c-api/init\_config.html#c.PyConfig\_GetInt>. Availability: Python 3.9 and newer. Not available on PyPy and not on the limited C API. [**int PyUnstable\_Object\_IsUniquelyReferenced(PyObject \*op)**](#int~27) See PyUnstable\_Object\_IsUniquelyReferenced() documentation <https://docs.python.org/dev/c-api/object.html#c.PyUnstable\_Object\_IsUniquelyReferenced>. Not available on PyPy. **Py\_REFCNT()** semantics is different on PyPy. Not available on the limited C API. [**int PyUnstable\_TryIncRef(PyObject \*op)**](#int~28) See PyUnstable\_TryIncRef() documentation <https://docs.python.org/dev/c-api/object.html#c.PyUnstable\_TryIncRef>. Not available on PyPy. **Py\_REFCNT()** semantics is different on PyPy. [**void PyUnstable\_EnableTryIncRef(PyObject \*op)**](#void~7) See PyUnstable\_EnableTryIncRef() documentation <https://docs.python.org/dev/c-api/object.html#c.PyUnstable\_EnableTryIncRef>. Not available on PyPy. **Py\_REFCNT()** semantics is different on PyPy. **PyObject \*PyImport\_ImportModuleAttr(PyObject \*mod\_name, PyObject \*attr\_name)** See PyImport\_ImportModuleAttr() documentation <https://docs.python.org/dev/c-api/import.html#c.PyImport\_ImportModuleAttr>. **PyObject \*PyImport\_ImportModuleAttrString(const char \*mod\_name, const char \*attr\_name)** See PyImport\_ImportModuleAttrString() documentation <https://docs.python.org/dev/c-api/import.html#c.PyImport\_ImportModuleAttrString>. [**uint32\_t Py\_PACK\_FULL\_VERSION(int major, int minor, int micro, int release\_level, int release\_serial)**](#uint32_t) See Py\_PACK\_FULL\_VERSION() documentation <https://docs.python.org/dev/c-api/apiabiversion.html#c.Py\_PACK\_FULL\_VERSION>. [**uint32\_t Py\_PACK\_VERSION(int major, int minor)**](#uint32_t~2) See Py\_PACK\_VERSION() documentation <https://docs.python.org/dev/c-api/apiabiversion.html#c.Py\_PACK\_VERSION>. Not supported: - **PyConfig\_Names()** - **PyConfig\_Set()** - **PyInitConfig\_AddModule()** - **PyInitConfig\_Create()** - **PyInitConfig\_Free()** - **PyInitConfig\_FreeStrList()** - **PyInitConfig\_GetError()** - **PyInitConfig\_GetExitCode()** - **PyInitConfig\_GetInt()** - **PyInitConfig\_GetStr()** - **PyInitConfig\_GetStrList()** - **PyInitConfig\_HasOption()** - **PyInitConfig\_SetInt()** - **PyInitConfig\_SetStr()** - **PyInitConfig\_SetStrList()** - **PyMonitoring\_FireBranchLeftEvent()** - **PyMonitoring\_FireBranchRightEvent()** - **PyType\_Freeze()** - **PyType\_GetBaseByToken()** - **PyUnicodeWriter\_DecodeUTF8Stateful()** - **PyUnstable\_IsImmortal()** - **PyUnstable\_Object\_EnableDeferredRefcount()** - **PyUnstable\_Object\_IsUniqueReferencedTemporary()** - **Py\_InitializeFromInitConfig()** ## [Python 3.13](#Python_3.13) **PyObject \*Py\_GetConstant(unsigned int constant\_id)** See Py\_GetConstant() documentation <https://docs.python.org/dev/c-api/object.html#c.Py\_GetConstant>. [**int PyDict\_GetItemRef(PyObject \*p, PyObject \*key, PyObject \*\*result)**](#int~29) See PyDict\_GetItemRef() documentation <https://docs.python.org/dev/c-api/dict.html#c.PyDict\_GetItemRef>. [**int PyDict\_GetItemStringRef(PyObject \*p, const char \*key, PyObject \*\*result)**](#int~30) See PyDict\_GetItemStringRef() documentation <https://docs.python.org/dev/c-api/dict.html#c.PyDict\_GetItemStringRef>. **PyObject \*PyImport\_AddModuleRef(const char \*name)** See PyImport\_AddModuleRef() documentation <https://docs.python.org/dev/c-api/import.html#c.PyImport\_AddModuleRef>. [**int PyObject\_GetOptionalAttr(PyObject \*obj, PyObject \*attr\_name, PyObject \*\*result)**](#int~31) See PyObject\_GetOptionalAttr() documentation <https://docs.python.org/dev/c-api/object.html#c.PyObject\_GetOptionalAttr>. [**int PyObject\_GetOptionalAttrString(PyObject \*obj, const char \*attr\_name, PyObject \*\*result)**](#int~32) See PyObject\_GetOptionalAttrString() documentation <https://docs.python.org/dev/c-api/object.html#c.PyObject\_GetOptionalAttrString>. [**int PyObject\_HasAttrWithError(PyObject \*obj, PyObject \*attr\_name)**](#int~33) See PyObject\_HasAttrWithError() documentation <https://docs.python.org/dev/c-api/object.html#c.PyObject\_HasAttrWithError>. [**int PyObject\_HasAttrStringWithError(PyObject \*obj, const char \*attr\_name)**](#int~34) See PyObject\_HasAttrStringWithError() documentation <https://docs.python.org/dev/c-api/object.html#c.PyObject\_HasAttrStringWithError>. [**int PyMapping\_GetOptionalItem(PyObject \*obj, PyObject \*key, PyObject \*\*result)**](#int~35) See PyMapping\_GetOptionalItem() documentation <https://docs.python.org/dev/c-api/mapping.html#c.PyMapping\_GetOptionalItem>. [**int PyMapping\_GetOptionalItemString(PyObject \*obj, const char \*key, PyObject \*\*result)**](#int~36) See PyMapping\_GetOptionalItemString() documentation <https://docs.python.org/dev/c-api/mapping.html#c.PyMapping\_GetOptionalItemString>. [**int PyMapping\_HasKeyWithError(PyObject \*obj, PyObject \*key)**](#int~37) See PyMapping\_HasKeyWithError() documentation <https://docs.python.org/dev/c-api/mapping.html#c.PyMapping\_HasKeyWithError>. [**int PyMapping\_HasKeyStringWithError(PyObject \*obj, const char \*key)**](#int~38) See PyMapping\_HasKeyStringWithError() documentation <https://docs.python.org/dev/c-api/mapping.html#c.PyMapping\_HasKeyStringWithError>. [**int PyModule\_Add(PyObject \*module, const char \*name, PyObject \*value)**](#int~39) See PyModule\_Add() documentation <https://docs.python.org/dev/c-api/module.html#c.PyModule\_Add>. [**int PyWeakref\_GetRef(PyObject \*ref, PyObject \*\*pobj)**](#int~40) See PyWeakref\_GetRef() documentation <https://docs.python.org/dev/c-api/weakref.html#c.PyWeakref\_GetRef>. [**int Py\_IsFinalizing()**](#int~41) Return non-zero if the Python interpreter is shutting down, return 0 otherwise. Availability: Python 3.3 and newer, PyPy 7.3 and newer, limited C API 3.13. See Py\_IsFinalizing() documentation <https://docs.python.org/dev/c-api/init.html#c.Py\_IsFinalizing>. [**int PyDict\_ContainsString(PyObject \*p, const char \*key)**](#int~42) See PyDict\_ContainsString() documentation <https://docs.python.org/dev/c-api/dict.html#c.PyDict\_ContainsString>. [**int PyLong\_AsInt(PyObject \*obj)**](#int~43) See PyLong\_AsInt() documentation <https://docs.python.org/dev/c-api/long.html#c.PyLong\_AsInt>. [**int PyObject\_VisitManagedDict(PyObject \*obj, visitproc visit, void \*arg)**](#int~44) See PyObject\_VisitManagedDict() documentation <https://docs.python.org/dev/c-api/object.html#c.PyObject\_VisitManagedDict>. Availability: Python 3.11 and newer. Not available on the limited C API. [**void PyObject\_ClearManagedDict(PyObject \*obj)**](#void~8) See PyObject\_ClearManagedDict() documentation <https://docs.python.org/dev/c-api/object.html#c.PyObject\_ClearManagedDict>. Availability: Python 3.11 and newer. Not available on the limited C API. **PyThreadState \*PyThreadState\_GetUnchecked(void)** See PyThreadState\_GetUnchecked() documentation <https://docs.python.org/dev/c-api/init.html#c.PyThreadState\_GetUnchecked>. Available on Python 3.5.2 and newer. Not available on the limited C API. [**int PyUnicode\_EqualToUTF8(PyObject \*unicode, const char \*str)**](#int~45) See PyUnicode\_EqualToUTF8() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicode\_EqualToUTF8>. [**int PyUnicode\_EqualToUTF8AndSize(PyObject \*unicode, const char \*str, Py\_ssize\_t size)**](#int~46) See PyUnicode\_EqualToUTF8AndSize() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicode\_EqualToUTF8AndSize>. [**int PyList\_Extend(PyObject \*list, PyObject \*iterable)**](#int~47) See PyList\_Extend() documentation <https://docs.python.org/dev/c-api/list.html#c.PyList\_Extend>. [**int PyList\_Clear(PyObject \*list)**](#int~48) See PyList\_Clear() documentation <https://docs.python.org/dev/c-api/list.html#c.PyList\_Clear>. [**int PyDict\_Pop(PyObject \*dict, PyObject \*key, PyObject \*\*result)**](#int~49) See PyDict\_Pop() documentation <https://docs.python.org/dev/c-api/dict.html#c.PyDict\_Pop>. [**int PyDict\_PopString(PyObject \*dict, const char \*key, PyObject \*\*result)**](#int~50) See PyDict\_PopString() documentation <https://docs.python.org/dev/c-api/dict.html#c.PyDict\_PopString>. [**Py\_hash\_t Py\_HashPointer(const void \*ptr)**](#Py_hash_t~3) See Py\_HashPointer() documentation <https://docs.python.org/dev/c-api/hash.html#c.Py\_HashPointer>. [**Py\_hash\_t PyObject\_GenericHash(PyObject \*obj)**](#Py_hash_t~4) See PyObject\_GenericHash() documentation <https://docs.python.org/dev/c-api/hash.html#c.PyObject\_GenericHash>. [**type PyTime\_t**](#type) A timestamp or duration in nanoseconds, represented as a signed 64-bit integer. Not available on the limited C API. [**PyTime\_t <#c.PyTime\_t> PyTime\_MIN**](#PyTime_t) Minimum value of **PyTime\_t**. Not available on the limited C API. [**PyTime\_t <#c.PyTime\_t> PyTime\_MAX**](#PyTime_t~2) Maximum value of **PyTime\_t**. Not available on the limited C API. [**double PyTime\_AsSecondsDouble(PyTime\_t <#c.PyTime\_t> t)**](#double) See PyTime\_AsSecondsDouble() documentation <https://docs.python.org/dev/c-api/time.html#c.PyTime\_AsSecondsDouble>. Not available on the limited C API. [**int PyTime\_Monotonic(PyTime\_t <#c.PyTime\_t> \*result)**](#int~51) See PyTime\_Monotonic() documentation <https://docs.python.org/dev/c-api/time.html#c.PyTime\_Monotonic>. Not available on the limited C API. [**int PyTime\_Time(PyTime\_t <#c.PyTime\_t> \*result)**](#int~52) See PyTime\_Time() documentation <https://docs.python.org/dev/c-api/time.html#c.PyTime\_Time>. Not available on the limited C API. [**int PyTime\_PerfCounter(PyTime\_t <#c.PyTime\_t> \*result)**](#int~53) See PyTime\_PerfCounter() documentation <https://docs.python.org/dev/c-api/time.html#c.PyTime\_PerfCounter>. Not available on the limited C API. **PyObject \*PyList\_GetItemRef(PyObject \*op, Py\_ssize\_t index)** See PyList\_GetItemRef() documentation <https://docs.python.org/dev/c-api/list.html#c.PyList\_GetItemRef>. [**int PyDict\_SetDefaultRef(PyObject \*d, PyObject \*key, PyObject \*default\_value, PyObject \*\*result)**](#int~54) See PyDict\_SetDefaultRef() documentation <https://docs.python.org/dev/c-api/dict.html#c.PyDict\_SetDefaultRef>. **PyObject \*PyType\_GetModuleName(PyTypeObject \*type)** See PyType\_GetModuleName() documentation <https://docs.python.org/dev/c-api/type.html#c.PyType\_GetModuleName>. **PyObject \*PyType\_GetFullyQualifiedName(PyTypeObject \*type)** See PyType\_GetFullyQualifiedName() documentation <https://docs.python.org/dev/c-api/type.html#c.PyType\_GetFullyQualifiedName>. **PyObject \*PyEval\_GetFrameLocals(void)** See PyEval\_GetFrameLocals() documentation <https://docs.python.org/dev/c-api/reflection.html#c.PyEval\_GetFrameLocals>. **PyObject \*PyEval\_GetFrameGlobals(void)** See PyEval\_GetFrameGlobals() documentation <https://docs.python.org/dev/c-api/reflection.html#c.PyEval\_GetFrameGlobals>. **PyObject \*PyEval\_GetFrameBuiltins(void)** See PyEval\_GetFrameBuiltins() documentation <https://docs.python.org/dev/c-api/reflection.html#c.PyEval\_GetFrameBuiltins>. [**Py\_BEGIN\_CRITICAL\_SECTION(op)**](#Py_BEGIN_CRITICAL_SECTION%28op%29) [**Py\_END\_CRITICAL\_SECTION()**](#Py_END_CRITICAL_SECTION%28%29) [**Py\_BEGIN\_CRITICAL\_SECTION2(a, b)**](#Py_BEGIN_CRITICAL_SECTION2%28a,) [**Py\_END\_CRITICAL\_SECTION2()**](#Py_END_CRITICAL_SECTION2%28%29) See Py\_BEGIN\_CRITICAL\_SECTION() documentation <https://docs.python.org/dev/c-api/synchronization.html#c.Py\_BEGIN\_CRITICAL\_SECTION>. Not supported: - **PyErr\_FormatUnraisable()**. - **PyLong\_AsNativeBytes()** - **PyLong\_FromNativeBytes()** - **PyLong\_FromUnsignedNativeBytes()** - **PyMonitoring\_EnterScope()** - **PyMonitoring\_ExitScope()** - **PyMonitoring\_FireCRaiseEvent()** - **PyMonitoring\_FireCReturnEvent()** - **PyMonitoring\_FireCallEvent()** - **PyMonitoring\_FireExceptionHandledEvent()** - **PyMonitoring\_FireJumpEvent()** - **PyMonitoring\_FireLineEvent()** - **PyMonitoring\_FirePyResumeEvent()** - **PyMonitoring\_FirePyReturnEvent()** - **PyMonitoring\_FirePyStartEvent()** - **PyMonitoring\_FirePyThrowEvent()** - **PyMonitoring\_FirePyUnwindEvent()** - **PyMonitoring\_FirePyYieldEvent()** - **PyMonitoring\_FireRaiseEvent()** - **PyMonitoring\_FireReraiseEvent()** - **PyMonitoring\_FireStopIterationEvent()** - **PyMutex\_Lock()** - **PyMutex\_Unlock()** - **PyRefTracer\_GetTracer()** - **PyRefTracer\_SetTracer()** - **PySys\_Audit()** - **PySys\_AuditTuple()** - **PyTime\_MonotonicRaw()** - **PyTime\_PerfCounterRaw()** - **PyTime\_TimeRaw()** ## [Python 3.12](#Python_3.12) **PyObject \*PyFrame\_GetVar(PyFrameObject \*frame, PyObject \*name)** See PyFrame\_GetVar() documentation <https://docs.python.org/dev/c-api/frame.html#c.PyFrame\_GetVar>. Not available on PyPy nor with the limited C API. **PyObject \*PyFrame\_GetVarString(PyFrameObject \*frame, const char \*name)** See PyFrame\_GetVarString() documentation <https://docs.python.org/dev/c-api/frame.html#c.PyFrame\_GetVarString>. Not available on PyPy nor with the limited C API. **PyObject \*Py\_GetConstantBorrowed(unsigned int constant\_id)** See Py\_GetConstantBorrowed() documentation <https://docs.python.org/dev/c-api/object.html#c.Py\_GetConstantBorrowed>. Not supported: - **PyCode\_AddWatcher()** - **PyCode\_ClearWatcher()** - **PyDict\_AddWatcher()** - **PyDict\_Watch()** - **PyErr\_DisplayException()** - **PyErr\_GetRaisedException()** - **PyErr\_SetRaisedException()** - **PyEval\_SetProfileAllThreads()** - **PyEval\_SetTraceAllThreads()** - **PyException\_GetArgs()** - **PyException\_SetArgs()** - **PyFunction\_SetVectorcall()** - **PyObject\_GetTypeData()** - **PyType\_AddWatcher()** - **PyType\_FromMetaclass()** (implementation too big to be backported) - **PyType\_Watch()** - **PyUnstable\_Code\_GetExtra()** - **PyUnstable\_Code\_New()** - **PyUnstable\_Code\_NewWithPosOnlyArgs()** - **PyUnstable\_Code\_SetExtra()** - **PyUnstable\_Eval\_RequestCodeExtraIndex()** - **PyVectorcall\_Call()** - **Py\_NewInterpreterFromConfig()** ## [Python 3.11](#Python_3.11) **PyObject \*PyCode\_GetCellvars(PyCodeObject \*code)** See PyCode\_GetCellvars() documentation <https://docs.python.org/dev/c-api/code.html#c.PyCode\_GetCellvars>. Not available on PyPy nor on limited C API 3.10 and older. **PyObject \*PyCode\_GetCode(PyCodeObject \*code)** See PyCode\_GetCode() documentation <https://docs.python.org/dev/c-api/code.html#c.PyCode\_GetCode>. Not available on PyPy nor on limited C API 3.10 and older. **PyObject \*PyCode\_GetFreevars(PyCodeObject \*code)** See PyCode\_GetFreevars() documentation <https://docs.python.org/dev/c-api/code.html#c.PyCode\_GetFreevars>. Not available on PyPy nor on limited C API 3.10 and older. **PyObject \*PyCode\_GetVarnames(PyCodeObject \*code)** See PyCode\_GetVarnames() documentation <https://docs.python.org/dev/c-api/code.html#c.PyCode\_GetVarnames>. Not available on PyPy nor on limited C API 3.10 and older. **PyObject \*PyFrame\_GetBuiltins(PyFrameObject \*frame)** See PyFrame\_GetBuiltins() documentation <https://docs.python.org/dev/c-api/frame.html#c.PyFrame\_GetBuiltins>. Not available on PyPy nor on limited C API 3.10 and older. **PyObject \*PyFrame\_GetGlobals(PyFrameObject \*frame)** See PyFrame\_GetGlobals() documentation <https://docs.python.org/dev/c-api/frame.html#c.PyFrame\_GetGlobals>. Not available on PyPy. [**int PyFrame\_GetLasti(PyFrameObject \*frame)**](#int~55) See PyFrame\_GetLasti() documentation <https://docs.python.org/dev/c-api/frame.html#c.PyFrame\_GetLasti>. Not available on PyPy nor on limited C API 3.10 and older. **PyObject \*PyFrame\_GetLocals(PyFrameObject \*frame)** See PyFrame\_GetLocals() documentation <https://docs.python.org/dev/c-api/frame.html#c.PyFrame\_GetLocals>. Not available on PyPy nor on limited C API 3.10 and older. [**void PyThreadState\_EnterTracing(PyThreadState \*tstate)**](#void~9) See PyThreadState\_EnterTracing() documentation <https://docs.python.org/dev/c-api/init.html#c.PyThreadState\_EnterTracing>. Not available on PyPy nor on limited C API 3.10 and older. [**void PyThreadState\_LeaveTracing(PyThreadState \*tstate)**](#void~10) See PyThreadState\_LeaveTracing() documentation <https://docs.python.org/dev/c-api/init.html#c.PyThreadState\_LeaveTracing>. Not available on PyPy nor on limited C API 3.10 and older. [**int PyFloat\_Pack2(double x, unsigned char \*p, int le)**](#int~56) Pack a C double as the IEEE 754 binary16 half-precision format. Availability: Python 3.6 and newer. Not available on PyPy nor on limited C API. [**int PyFloat\_Pack4(double x, unsigned char \*p, int le)**](#int~57) Pack a C double as the IEEE 754 binary32 single precision format. Not available on PyPy nor on limited C API. [**int PyFloat\_Pack8(double x, unsigned char \*p, int le)**](#int~58) Pack a C double as the IEEE 754 binary64 double precision format. Not available on PyPy nor on limited C API. [**double PyFloat\_Unpack2(const unsigned char \*p, int le)**](#double~2) Unpack the IEEE 754 binary16 half-precision format as a C double. Availability: Python 3.6 and newer. Not available on PyPy nor on limited C API. [**double PyFloat\_Unpack4(const unsigned char \*p, int le)**](#double~3) Unpack the IEEE 754 binary32 single precision format as a C double. Not available on PyPy nor on limited C API. [**double PyFloat\_Unpack8(const unsigned char \*p, int le)**](#double~4) Unpack the IEEE 754 binary64 double precision format as a C double. Not available on PyPy nor on limited C API. **PyObject \*PyType\_GetName(PyTypeObject \*type)** See PyType\_GetName() documentation <https://docs.python.org/dev/c-api/type.html#c.PyType\_GetName>. **PyObject \*PyType\_GetQualName(PyTypeObject \*type)** See PyType\_GetQualName() documentation <https://docs.python.org/dev/c-api/type.html#c.PyType\_GetQualName>. Not supported: - **PyErr\_GetHandledException()** - **PyErr\_SetHandledException()** - **PyFrame\_GetGenerator()** - **PyType\_GetModuleByDef()** - **Py\_Version** constant ## [Python 3.10](#Python_3.10) **PyObject \*Py\_NewRef(PyObject \*obj)** See Py\_NewRef() documentation <https://docs.python.org/dev/c-api/refcounting.html#c.Py\_NewRef>. **PyObject \*Py\_XNewRef(PyObject \*obj)** See Py\_XNewRef() documentation <https://docs.python.org/dev/c-api/refcounting.html#c.Py\_XNewRef>. [**int Py\_Is(PyObject \*x, PyObject \*y)**](#int~59) See Py\_Is() documentation <https://docs.python.org/dev/c-api/structures.html#c.Py\_Is>. [**int Py\_IsNone(PyObject \*x)**](#int~60) See Py\_IsNone() documentation <https://docs.python.org/dev/c-api/structures.html#c.Py\_IsNone>. [**int Py\_IsTrue(PyObject \*x)**](#int~61) See Py\_IsTrue() documentation <https://docs.python.org/dev/c-api/structures.html#c.Py\_IsTrue>. [**int Py\_IsFalse(PyObject \*x)**](#int~62) See Py\_IsFalse() documentation <https://docs.python.org/dev/c-api/structures.html#c.Py\_IsFalse>. [**int PyModule\_AddObjectRef(PyObject \*module, const char \*name, PyObject \*value)**](#int~63) See PyModule\_AddObjectRef() documentation <https://docs.python.org/dev/c-api/module.html#c.PyModule\_AddObjectRef>. Not supported: - **PyCodec\_Unregister()** - **PyDateTime\_DATE\_GET\_TZINFO()** - **PyDateTime\_TIME\_GET\_TZINFO()** - **PyErr\_SetInterruptEx()** - **PyGC\_Disable()** - **PyGC\_Enable()** - **PyGC\_IsEnabled()** - **PyIter\_Send()** - **PySet\_CheckExact()** - **Py\_TPFLAGS\_DISALLOW\_INSTANTIATION** constant - **Py\_TPFLAGS\_IMMUTABLETYPE** constant ## [Python 3.9](#Python_3.9) ## [PyObject](#PyObject) [**void Py\_SET\_REFCNT(PyObject \*ob, Py\_ssize\_t refcnt)**](#void~11) See Py\_SET\_REFCNT() documentation <https://docs.python.org/dev/c-api/structures.html#c.Py\_SET\_REFCNT>. [**void Py\_SET\_TYPE(PyObject \*ob, PyTypeObject \*type)**](#void~12) See Py\_SET\_TYPE() documentation <https://docs.python.org/dev/c-api/structures.html#c.Py\_SET\_TYPE>. [**void Py\_SET\_SIZE(PyVarObject \*ob, Py\_ssize\_t size)**](#void~13) See Py\_SET\_SIZE() documentation <https://docs.python.org/dev/c-api/structures.html#c.Py\_SET\_SIZE>. [**int Py\_IS\_TYPE(const PyObject \*ob, const PyTypeObject \*type)**](#int~64) See Py\_IS\_TYPE() documentation <https://docs.python.org/dev/c-api/structures.html#c.Py\_IS\_TYPE>. **PyObject \*PyObject\_CallNoArgs(PyObject \*func)** See PyObject\_CallNoArgs() documentation <https://docs.python.org/dev/c-api/call.html#c.PyObject\_CallNoArgs>. **PyObject \*PyObject\_CallOneArg(PyObject \*func, PyObject \*arg)** See PyObject\_CallOneArg() documentation <https://docs.python.org/dev/c-api/call.html#c.PyObject\_CallOneArg>. **PyObject \*PyObject\_Vectorcall(PyObject \*callable, PyObject \*const \*args, size\_t nargsf, PyObject \*kwnames)** See PyObject\_Vectorcall() documentation <https://docs.python.org/dev/c-api/call.html#c.PyObject\_Vectorcall>. [**Py\_ssize\_t PyVectorcall\_NARGS(size\_t nargsf)**](#Py_ssize_t~2) See PyVectorcall\_NARGS() documentation <https://docs.python.org/dev/c-api/call.html#c.PyVectorcall\_NARGS>. [**PY\_VECTORCALL\_ARGUMENTS\_OFFSET**](#PY_VECTORCALL_ARGUMENTS_OFFSET) See PY\_VECTORCALL\_ARGUMENTS\_OFFSET documentation <https://docs.python.org/dev/c-api/call.html#PY\_VECTORCALL\_ARGUMENTS\_OFFSET>. ## [PyFrameObject](#PyFrameObject) [**PyCodeObject \*PyFrame\_GetCode(PyFrameObject \*frame)**](#PyCodeObject) See PyFrame\_GetCode() documentation <https://docs.python.org/dev/c-api/reflection.html#c.PyFrame\_GetCode>. Not available on limited C API 3.8 and older. **PyFrameObject \*PyFrame\_GetBack(PyFrameObject \*frame)** See PyFrame\_GetBack() documentation <https://docs.python.org/dev/c-api/reflection.html#c.PyFrame\_GetBack>. Not available on PyPy nor with the limited C API. ## [PyThreadState](#PyThreadState) **PyFrameObject \*PyThreadState\_GetFrame(PyThreadState \*tstate)** See PyThreadState\_GetFrame() documentation <https://docs.python.org/dev/c-api/init.html#c.PyThreadState\_GetFrame>. Availability: PyPy 3.11 and newer, and limited C API 3.9. **PyInterpreterState \*PyThreadState\_GetInterpreter(PyThreadState \*tstate)** See PyThreadState\_GetInterpreter() documentation <https://docs.python.org/dev/c-api/init.html#c.PyThreadState\_GetInterpreter>. Not available on limited C API 3.8 and older. [**uint64\_t PyThreadState\_GetID(PyThreadState \*tstate)**](#uint64_t) See PyThreadState\_GetID() documentation <https://docs.python.org/dev/c-api/init.html#c.PyThreadState\_GetID>. Availability: Python 3.7. Not available on PyPy nor on limited C API 3.8 and older. ## [PyInterpreterState](#PyInterpreterState) **PyInterpreterState \*PyInterpreterState\_Get(void)** See PyInterpreterState\_Get() documentation <https://docs.python.org/dev/c-api/init.html#c.PyInterpreterState\_Get>. Not available on limited C API 3.8 and older on Unix. Not available in stable ABI 3.9 and older on Windows. ## [GC protocol](#GC_protocol) [**int PyObject\_GC\_IsTracked(PyObject \*obj)**](#int~65) See PyObject\_GC\_IsTracked() documentation <https://docs.python.org/dev/c-api/gcsupport.html#c.PyObject\_GC\_IsTracked>. Not available on PyPy nor on limited C API 3.9 and older. [**int PyObject\_GC\_IsFinalized(PyObject \*obj)**](#int~66) See PyObject\_GC\_IsFinalized() documentation <https://docs.python.org/dev/c-api/gcsupport.html#c.PyObject\_GC\_IsFinalized>. Availability: Python 3.4. Not available on PyPy nor on limited C API 3.9 and older. ## [Module helper](#Module_helper) [**int PyModule\_AddType(PyObject \*module, PyTypeObject \*type)**](#int~67) See PyModule\_AddType() documentation <https://docs.python.org/dev/c-api/module.html#c.PyModule\_AddType>. ## [Not supported](#Not_supported) - **PyObject\_VectorcallMethod()** - **PyType\_FromModuleAndSpec()** - **PyType\_GetModule()** - **PyType\_GetModuleState()** - **PyVectorcall\_CallMethod()** ## [Python 3.8](#Python_3.8) Not supported: • **PyCode\_NewWithPosOnlyArgs()**. ## [Python 3.7](#Python_3.7) Not supported: - **PyContextToken\_CheckExact()** - **PyContextToken\_CheckExact()** - **PyContextVar\_CheckExact()** - **PyContextVar\_Get()** - **PyContextVar\_New()** - **PyContextVar\_Reset()** - **PyContextVar\_Set()** - **PyContext\_AddWatcher()** - **PyContext\_CheckExact()** - **PyContext\_ClearWatcher()** - **PyContext\_Copy()** - **PyContext\_CopyCurrent()** - **PyContext\_Enter()** - **PyContext\_Exit()** - **PyContext\_New()** - **PyImport\_GetModule()** - **PyInterpreterState\_GetID()** - **PyOS\_AfterFork\_Child()** - **PyOS\_AfterFork\_Parent()** - **PyOS\_BeforeFork()** - **PySlice\_AdjustIndices()** - **PySlice\_Unpack()** - **PyThread\_tss\_alloc()** - **PyThread\_tss\_create()** - **PyThread\_tss\_delete()** - **PyThread\_tss\_free()** - **PyThread\_tss\_get()** - **PyThread\_tss\_is\_created()** - **PyThread\_tss\_set()** - **PyTimeZone\_FromOffset()** - **PyTimeZone\_FromOffsetAndName()** - **PyTraceMalloc\_Track()** - **PyTraceMalloc\_Untrack()** - **Py\_RETURN\_RICHCOMPARE()** - **Py\_UNREACHABLE** macro ## [Python 3.6](#Python_3.6) Not supported: - **PyErr\_ResourceWarning()**. - **PyErr\_SetImportErrorSubclass()**. - **PyOS\_FSPath()**. - **Py\_FinalizeEx()**. ## [Python 3.5](#Python_3.5) [**Py\_SETREF(op, op2)**](#Py_SETREF%28op,) [**Py\_XSETREF(op, op2)**](#Py_XSETREF%28op,) Not supported: - **PyCodec\_NameReplaceErrors()** - **PyErr\_FormatV()** - **PyExc\_RecursionError** - **PyMem\_Calloc()** - **PyMem\_RawCalloc()** - **PyModule\_ExecDef()** - **PyModule\_FromDefAndSpec()** - **PyModule\_FromDefAndSpec2()** - **PyNumber\_InPlaceMatrixMultiply()** - **PyNumber\_MatrixMultiply()** - **PyObject\_Calloc()** - **Py\_DecodeLocale()** - **Py\_EncodeLocale()** ## [Python 3.4](#Python_3.4) [**Py\_UNUSED(name)**](#Py_UNUSED%28name%29) See Py\_UNUSED() documentation <https://docs.python.org/dev/c-api/intro.html#c.Py\_UNUSED>. Not supported: - **PyObject\_LengthHint()** - **PyStructSequence\_InitType2()** - **PyType\_GetSlot()** - **Py\_SetStandardStreamEncoding()** ## [Python 3.3](#Python_3.3) Not supported: - **PyMemoryView\_FromMemory()** - **PyUnicode\_AsUCS4()** - **PyUnicode\_AsUCS4Copy()** - **PyUnicode\_CopyCharacters()** - **PyUnicode\_FindChar()** - **PyUnicode\_FromKindAndData()** - **PyUnicode\_GET\_LENGTH()** - **PyUnicode\_GetLength()** - **PyUnicode\_New()** - **PyUnicode\_ReadChar()** - **PyUnicode\_Substring()** - **PyUnicode\_WriteChar()** ## [Python 3.2](#Python_3.2) Not supported: - **Py\_VA\_COPY**. - **PySys\_SetArgvEx()**. - **PyLong\_AsLongLongAndOverflow()**. - **PyErr\_NewExceptionWithDoc()**. ## [Python 3.1](#Python_3.1) Not supported: - **PyCapsule\_CheckExact()** - **PyCapsule\_GetContext()** - **PyCapsule\_GetDestructor()** - **PyCapsule\_GetName()** - **PyCapsule\_GetPointer()** - **PyCapsule\_Import()** - **PyCapsule\_IsValid()** - **PyCapsule\_New()** - **PyCapsule\_SetContext()** - **PyCapsule\_SetDestructor()** - **PyCapsule\_SetName()** - **PyCapsule\_SetPointer()** - **PyOS\_string\_to\_double()** ## [Python 3.0](#Python_3.0) There are too many changes compared to Python 2.7, but it's no longer useful to document them. # [PYTHONCAPI-COMPAT USERS](#PYTHONCAPI-COMPAT_USERS) ## [Examples of projects using pythoncapi\_compat.h](#Examples_of_projects_using_pythoncapi_compat.h) - bitarray <https://github.com/ilanschnell/bitarray/>: **bitarray/\_bitarray.c** uses **Py\_SET\_SIZE()** (pythoncapi\_compat.h copy <https://github.com/ilanschnell/bitarray/blob/master/bitarray/pythoncapi\_compat.h>) - datatable <https://github.com/h2oai/datatable> (commit <https://github.com/h2oai/datatable/commit/02f13114828ed4567e4410f5bac579895e20355a>) - guppy3 <https://github.com/zhuyifei1999/guppy3/> (commit <https://github.com/zhuyifei1999/guppy3/commit/4cb9fcb5d75327544a6875b6caabfdffb70a7e29>) - immutables <https://github.com/MagicStack/immutables/>: **immutables/\_map.c** uses **Py\_SET\_SIZE()** (pythoncapi\_compat.h copy <https://github.com/MagicStack/immutables/blob/master/immutables/pythoncapi\_compat.h>) - Mercurial (hg) <https://www.mercurial-scm.org/> uses **Py\_SET\_TYPE()** (commit <https://www.mercurial-scm.org/repo/hg/rev/e92ca942ddca>, pythoncapi\_compat.h copy <https://www.mercurial-scm.org/repo/hg/file/tip/mercurial/pythoncapi\_compat.h>) - mypy <https://github.com/python/mypy> (mypyc, commit <https://github.com/python/mypy/commit/2b7e2df923f7e4a3a199915b3c8563f45bc69dfa>) - numpy <https://numpy.org/>: pythoncapi-compat Git submodule <https://github.com/numpy/numpy/blob/main/.gitmodules> - pybluez <https://github.com/pybluez/pybluez> (commit <https://github.com/pybluez/pybluez/commit/5096047f90a1f6a74ceb250aef6243e144170f92>) - python-snappy <https://github.com/andrix/python-snappy/> (commit <https://github.com/andrix/python-snappy/commit/1a539d71d5b1ceaf9a2291f21f686cf53a46d707>) - python-zstandard <https://github.com/indygreg/python-zstandard/> uses **Py\_SET\_TYPE()** and **Py\_SET\_SIZE()** (commit <https://github.com/indygreg/python-zstandard/commit/e5a3baf61b65f3075f250f504ddad9f8612bfedf>): Mercurial extension. - python-zstd <https://github.com/sergey-dryabzhinsky/python-zstd/> (commit <https://github.com/sergey-dryabzhinsky/python-zstd/commit/8aa6d7a4b250e1f0a4e27b4107c39dc516c87f96>) - hollerith <https://github.com/pyansys/hollerith/> **src/writer.c** uses **PyObject\_CallOneArg() and other Python 3.9 apis** (pythoncapi\_compat.h copy <https://github.com/pyansys/hollerith/blob/main/src/pythoncapi\_compat.h>) - PyTorch <https://github.com/pytorch/pytorch/> (pythoncapi\_compat.h copy <https://github.com/pytorch/pytorch/blob/main/torch/csrc/utils/pythoncapi\_compat.h>) - PyGObject <https://gitlab.gnome.org/GNOME/pygobject/> (commit <https://gitlab.gnome.org/GNOME/pygobject/-/commit/074c0348417b87d3003dbb409e6fc26b61121de3>, pythoncapi-compat Meson subproject <https://gitlab.gnome.org/GNOME/pygobject/-/blob/main/subprojects/pythoncapi-compat.wrap?ref\_type=heads>) - Pillow <https://github.com/python-pillow/Pillow/> (src/thirdparty/pythoncapi\_compat.h <https://github.com/python-pillow/Pillow/blob/main/src/thirdparty/pythoncapi\_compat.h>) - watchdog <https://github.com/gorakhargosh/watchdog/> (src/pythoncapi\_compat.h <https://github.com/gorakhargosh/watchdog/blob/master/src/pythoncapi\_compat.h>) ## [Projects not using pythoncapi\_compat.h](#Projects_not_using_pythoncapi_compat.h) Projects not using **pythoncapi\_compat.h**: • Cython doesn't use pythoncapi\_compat.h: see Cython issue #3934 <https://github.com/cython/cython/issues/3934>. For example, ModuleSetupCode.c <https://github.com/cython/cython/blob/0.29.x/Cython/Utility/ModuleSetupCode.c> provides functions like **\_\_Pyx\_SET\_REFCNT()**. Project with a strict contributor agreement: • zodbpickle <https://github.com/zopefoundation/zodbpickle/pull/64> # [RUN TESTS](#RUN_TESTS) To run pythoncapi-compat tests, type: ``` python3 runtests.py ``` To only test the current Python version, use the **-c** or the **--current** option: ``` python3 runtests.py --current ``` Verbose mode (**-v**, **--verbose**): ``` python3 runtests.py --verbose ``` See tests in the **tests/** subdirectory. # [CHANGELOG](#CHANGELOG) • 2026-10-12: Add functions: - **PyEval\_GetFrameBuiltins()** - **PyEval\_GetFrameGlobals()** - **PyEval\_GetFrameLocals()** - 2026-10-12: Delete 5 **Borrow** functions which were specific to pythoncapi-compat and only used by the removed script **upgrade\_pythoncapi.py**: **\_Py\_StealRef()** **\_Py\_XStealRef()** **\_PyThreadState\_GetFrameBorrow()** **\_PyFrame\_GetCodeBorrow()** and **\_PyFrame\_GetBackBorrow()**. - 2026-10-11: Remove the **upgrade\_pythoncapi.py** script. - 2026-10-10: Add **PyObject\_GenericHash()** and **PyUnicodeWriter\_WriteUCS4()** functions. runtests.py now runs tests in parallel. - 2026-10-08: Add support for the limited C API 3.2. - 2026-10-08: Add functions: - **PyImport\_ImportModuleAttr()** - **PyImport\_ImportModuleAttrString()** - **PyType\_GetFullyQualifiedName()** - **PyType\_GetModuleName()** - **PyType\_GetName()** - **PyType\_GetQualName()** - 2026-10-04: Add support for the limited C API (**Py\_LIMITED\_API**). - 2026-09-23: **PyUnstable\_Object\_IsUniquelyReferenced()**, **PyUnstable\_TryIncRef()** and **PyUnstable\_EnableTryIncRef()** are no longer available on PyPy. **Py\_REFCNT()** semantics is different on PyPy. - 2026-09-22: Add support for PyPy3.12 v8.0.0, which provides **PyFrame\_GetCode()** and **PyInterpreterState\_Get()**. - 2026-09-07: Remove code to support Python 2.7, Python 3.5 and PyPy for Python 2.7 ("pypy2"). Python 2.7 was no longer supported since August 2023. Python 3.5 was no longer supported since October 2024. - 2026-02-12: Add functions: • **PyUnstable\_SetImmortal()** • 2025-10-14: Add functions: - **PyTuple\_FromArray()** - **PyUnstable\_Unicode\_GET\_CACHED\_HASH()** • 2025-09-18: Add PEP 782 functions: - **PyBytesWriter\_Create()** - **PyBytesWriter\_Discard()** - **PyBytesWriter\_Finish()** - **PyBytesWriter\_FinishWithPointer()** - **PyBytesWriter\_FinishWithSize()** - **PyBytesWriter\_Format()** - **PyBytesWriter\_GetData()** - **PyBytesWriter\_GetSize()** - **PyBytesWriter\_Grow()** - **PyBytesWriter\_GrowAndUpdatePointer()** - **PyBytesWriter\_Resize()** - **PyBytesWriter\_WriteBytes()** - 2025-09-01: Add **PyUnstable\_Object\_IsUniquelyReferenced()** function. - 2025-06-09: Add **PyUnicodeWriter\_WriteASCII()** function. - 2025-06-03: Add functions: - **PySys\_GetAttr()** - **PySys\_GetAttrString()** - **PySys\_GetOptionalAttr()** - **PySys\_GetOptionalAttrString()** - 2025-01-19: Add **PyConfig\_Get()** functions. - 2025-01-06: Add **Py\_fopen()** and **Py\_fclose()** functions. - 2024-12-16: Add **structmember.h** constants: - **Py\_T\_BOOL** - **Py\_T\_BYTE** - **Py\_T\_CHAR** - **Py\_T\_DOUBLE** - **Py\_T\_FLOAT** - **Py\_T\_INT** - **Py\_T\_LONGLONG** - **Py\_T\_LONG** - **Py\_T\_OBJECT\_EX** - **Py\_T\_PYSSIZET** - **Py\_T\_SHORT** - **Py\_T\_STRING\_INPLACE** - **Py\_T\_STRING** - **Py\_T\_UBYTE** - **Py\_T\_UINT** - **Py\_T\_ULONGLONG** - **Py\_T\_ULONG** - **Py\_T\_USHORT** - **\_Py\_T\_NONE** - **\_Py\_T\_OBJECT** - **Py\_AUDIT\_READ** - **Py\_READONLY** - **\_Py\_WRITE\_RESTRICTED** • 2024-12-13: Add functions and structs: - **PyLongLayout** - **PyLong\_GetNativeLayout()** - **PyLongExport** - **PyLong\_Export()** - **PyLong\_FreeExport()** - **PyLongWriter** - **PyLongWriter\_Create()** - **PyLongWriter\_Finish()** - **PyLongWriter\_Discard()** • 2024-11-12: Add functions: - **PyLong\_IsPositive()** - **PyLong\_IsNegative()** - **PyLong\_IsZero()** • 2024-10-09: Add functions: - **PyBytes\_Join()** - **PyIter\_NextItem()** - **PyLong\_AsInt32()** - **PyLong\_AsInt64()** - **PyLong\_AsUInt32()** - **PyLong\_AsUInt64()** - **PyLong\_FromInt32()** - **PyLong\_FromInt64()** - **PyLong\_FromUInt32()** - **PyLong\_FromUInt64()** - **PyUnicode\_Equal()** - **Py\_HashBuffer()** • 2024-07-18: Add functions: - **PyUnicodeWriter\_Create()** - **PyUnicodeWriter\_Discard()** - **PyUnicodeWriter\_Finish()** - **PyUnicodeWriter\_WriteChar()** - **PyUnicodeWriter\_WriteUTF8()** - **PyUnicodeWriter\_WriteStr()** - **PyUnicodeWriter\_WriteRepr()** - **PyUnicodeWriter\_WriteSubstring()** - **PyUnicodeWriter\_WriteWideChar()** - **PyUnicodeWriter\_Format()** - 2024-06-03: Add **PyLong\_GetSign()**. - 2024-04-23: Drop Python 3.5 support. It cannot be tested anymore (pip fails). - 2024-04-02: Add **PyDict\_SetDefaultRef()** function. - 2024-03-29: Add **PyList\_GetItemRef()** function. - 2024-03-21: Add functions: - **Py\_GetConstant()** - **Py\_GetConstantBorrowed()** • 2024-03-09: Add hash constants: - **PyHASH\_BITS** - **PyHASH\_IMAG** - **PyHASH\_INF** - **PyHASH\_MODULUS** • 2024-02-20: Add PyTime API: - **PyTime\_t** type - **PyTime\_MIN** and **PyTime\_MAX** constants - **PyTime\_AsSecondsDouble()** - **PyTime\_Monotonic()** - **PyTime\_PerfCounter()** - **PyTime\_Time()** - 2023-12-15: Add function **Py\_HashPointer()**. - 2023-11-14: Add functions: - **PyDict\_Pop()** - **PyDict\_PopString()** • 2023-11-13: Add functions: - **PyList\_Extend()** - **PyList\_Clear()** • 2023-10-04: Add functions: - **PyUnicode\_EqualToUTF8()** - **PyUnicode\_EqualToUTF8AndSize()** • 2023-10-03: Add functions: - **PyObject\_VisitManagedDict()** - **PyObject\_ClearManagedDict()** - **PyThreadState\_GetUnchecked()** • 2023-09-29: Add functions: - **PyMapping\_HasKeyWithError()** - **PyMapping\_HasKeyStringWithError()** - **PyObject\_HasAttrWithError()** - **PyObject\_HasAttrStringWithError()** - 2023-08-25: Add **PyDict\_ContainsString()** and **PyLong\_AsInt()** functions. - 2023-08-21: Remove support for Python 2.7, Python 3.4 and older. - 2023-08-16: Add **Py\_IsFinalizing()** function. - 2023-07-21: Add **PyDict\_GetItemRef()** function. - 2023-07-18: Add **PyModule\_Add()** function. - 2023-07-12: Add functions: - **PyObject\_GetOptionalAttr()** - **PyObject\_GetOptionalAttrString()** - **PyMapping\_GetOptionalItem()** - **PyMapping\_GetOptionalItemString()** - 2023-07-05: Add **PyObject\_Vectorcall()** function. - 2023-06-21: Add **PyWeakref\_GetRef()** function. - 2023-06-20: Add **PyImport\_AddModuleRef()** function. - 2022-11-15: Add experimental operations to the **upgrade\_pythoncapi.py** script: **Py\_NewRef**, **Py\_CLEAR** and **Py\_SETREF**. - 2022-11-09: Fix **Py\_SETREF()** and **Py\_XSETREF()** macros for gh-98724 <https://github.com/python/cpython/issues/98724>. - 2022-11-04: Add **PyFrame\_GetVar()** and **PyFrame\_GetVarString()** functions. - 2022-08-04: Add **PyCode\_GetVarnames()**, **PyCode\_GetFreevars()** and **PyCode\_GetCellvars()** functions. - 2022-06-14: Fix compatibility with C++ older than C++11. - 2022-05-03: Add **PyCode\_GetCode()** function. - 2022-04-26: Rename the project from **pythoncapi\_compat** to **pythoncapi-compat**: replace the underscore separator with a dash. - 2022-04-08: Add functions **PyFrame\_GetLocals()**, **PyFrame\_GetGlobals()** **PyFrame\_GetBuiltins()**, and **PyFrame\_GetLasti()**. - 2022-03-12: Add functions **PyFloat\_Pack2()**, **PyFloat\_Pack4()**, **PyFloat\_Pack8()**, **PyFloat\_Unpack2()**, **PyFloat\_Unpack4()** and **PyFloat\_Unpack8()**. - 2022-03-03: The project moved to <https://github.com/python/pythoncapi-compat> - 2022-02-11: The project license changes from the MIT license to the Zero Clause BSD (0BSD) license. Projects copying **pythoncapi\_compat.h** no longer have to include the MIT license and the copyright notice. - 2022-02-08: Add documentation. - 2022-02-09: **pythoncapi\_compat.h** now supports C++ on Python 3.6 and newer: use **nullptr** and **reinterpret\_cast<type>** cast on C++, and use **NULL** and **(type)** cast on C. - 2021-10-15: Add **PyThreadState\_EnterTracing()** and **PyThreadState\_LeaveTracing()**. - 2021-04-09: Add **Py\_Is()**, **Py\_IsNone()**, **Py\_IsTrue()**, **Py\_IsFalse()** functions. - 2021-04-01: - Add **Py\_SETREF()**, **Py\_XSETREF()** and **Py\_UNUSED()**. - Add PyPy support. - 2021-01-27: Fix compatibility with Visual Studio 2008 for Python 2.7. - 2020-11-30: Creation of the **upgrade\_pythoncapi.py** script. - 2020-06-04: Creation of the **pythoncapi\_compat.h** header file. # [LINKS](#LINKS) - Python/C API Reference Manual <https://docs.python.org/dev/c-api/> - HPy: a better API for Python <https://hpy.readthedocs.io/> - Cython: C-extensions for Python <https://cython.org/> - Old 2to3c project <https://github.com/davidmalcolm/2to3c> by David Malcolm which uses Coccinelle <https://coccinelle.gitlabpages.inria.fr/website/> to ease migration of C extensions from Python 2 to Python 3. See also 2to3c: an implementation of Python's 2to3 for C code <https://dmalcolm.livejournal.com/3935.html> article (2009). - PEPs related to the C API: - PEP 620 -- Hide implementation details from the C API <https://www.python.org/dev/peps/pep-0620/> - PEP 670 -- Convert macros to functions in the Python C API <https://www.python.org/dev/peps/pep-0670/> - PEP 674 -- Disallow using macros as l-values <https://www.python.org/dev/peps/pep-0674/> • Make structures opaque - bpo-39573: PyObject <https://bugs.python.org/issue39573> - bpo-40170: PyTypeObject <https://bugs.python.org/issue40170> - bpo-39947: PyThreadState <https://bugs.python.org/issue39947> - bpo-40421: PyFrameObject <https://bugs.python.org/issue40421> - bpo-47241: PyCodeObject <https://bugs.python.org/issue47241> This project is distributed under the Zero Clause BSD (0BSD) license <https://opensource.org/licenses/0BSD> and is covered by the PSF Code of Conduct <https://www.python.org/psf/codeofconduct/>. # [Author](#Author) Victor Stinner # [Copyright](#Copyright) 2022, Victor Stinner October 20, 2026 --- Document: pythoncapi_compat(1) from pythoncapi-compat 0_git20261020-r0 (Chainguard OS) Source: https://github.com/python/pythoncapi-compat.git