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.

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.

New in version 3.11.

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