API and ABI Versioning

CPython exposes its version number in the following macros. Note that these correspond to the version code is built with, not necessarily the version used at run time.

See C API Stability for a discussion of API and ABI stability across versions.

PY_MAJOR_VERSION¶: The 3 in 3.4.1a2.

PY_MINOR_VERSION¶: The 4 in 3.4.1a2.

PY_MICRO_VERSION¶: The 1 in 3.4.1a2.

PY_RELEASE_LEVEL¶: The a in 3.4.1a2. This can be 0xA for alpha, 0xB for beta, 0xC for release candidate or 0xF for final.

PY_RELEASE_SERIAL¶: The 2 in 3.4.1a2. Zero for final releases.

PY_VERSION_HEX¶

The Python version number encoded in a single integer.

The underlying version information can be found by treating it as a 32 bit number in the following manner:

Bytes	Bits (big endian order)	Meaning	Value for `3.4.1a2`
1	1-8	`PY_MAJOR_VERSION`	`0x03`
2	9-16	`PY_MINOR_VERSION`	`0x04`
3	17-24	`PY_MICRO_VERSION`	`0x01`
4	25-28	`PY_RELEASE_LEVEL`	`0xA`
4	29-32	`PY_RELEASE_SERIAL`	`0x2`

Thus 3.4.1a2 is hexversion 0x030401a2 and 3.10.0 is hexversion 0x030a00f0.

Use this for numeric comparisons, e.g. #if PY_VERSION_HEX >= ....

This version is also available via the symbol Py_Version.

const unsigned long Py_Version¶

Part of the Stable ABI since version 3.11.

The Python runtime version number encoded in a single constant integer, with the same format as the PY_VERSION_HEX macro. This contains the Python version used at run time.

Added in version 3.11.

All the given macros are defined in Include/patchlevel.h.