.. _sec_creating_subclasses_from_versioninfo: Creating Subclasses from Version ================================ .. meta:: :description lang=en: Creating subclasses from Version class If you do not like creating functions to modify the behavior of semver (as shown in section :ref:`sec_dealing_with_invalid_versions`), you can also create a subclass of the :class:`Version ` class. For example, if you want to output a "v" prefix before a version, but the other behavior is the same, use the following code: .. literalinclude:: semverwithvprefix.py :language: python :lines: 4- The derived class :class:`SemVerWithVPrefix` can be used like the original class. Additionally, you can pass "incomplete" version strings like ``v2.3``: .. code-block:: python >>> v1 = SemVerWithVPrefix.parse("v1.2.3") >>> assert str(v1) == "v1.2.3" >>> print(v1) v1.2.3 >>> v2 = SemVerWithVPrefix.parse("v2.3") >>> v2 > v1 True >>> bad = SemVerWithVPrefix.parse("1.2.4") Traceback (most recent call last): ... ValueError: '1.2.4': not a valid semantic version tag. Must start with 'v' or 'V'