Introduction

This small python library provides a few tools to handle SemVer in Python. It follows strictly the 2.0.0 version of the SemVer scheme.

Links

• Package on PyPI:

• Doc on ReadTheDocs:

• Source on GitHub:

• Build on Github Actions:

• Semantic Version specification: SemVer

Getting started

Install the package from PyPI, using pip:

pip install semantic-version

Or from GitHub:

$ git clone git://github.com/rbarrois/python-semanticversion.git

Import it in your code:

import semantic_version

This module provides classes to handle semantic versions:

• Version represents a version number (0.1.1-alpha+build.2012-05-15)
• BaseSpec-derived classes represent requirement specifications (>=0.1.1,<0.3.0):
  • SimpleSpec describes a natural description syntax
  • NpmSpec is used for NPM-style range descriptions.

Versions

Defining a Version is quite simple:

>>> import semantic_version
>>> v = semantic_version.Version('0.1.1')
>>> v.major
0
>>> v.minor
1
>>> v.patch
1
>>> v.prerelease
[]
>>> v.build
[]
>>> list(v)
[0, 1, 1, [], []]

If the provided version string is invalid, a ValueError will be raised:

>>> semantic_version.Version('0.1')
Traceback (most recent call last):
  File "", line 1, in 
  File "/Users/rbarrois/dev/semantic_version/src/semantic_version/base.py", line 64, in __init__
    major, minor, patch, prerelease, build = self.parse(version_string, partial)
  File "/Users/rbarrois/dev/semantic_version/src/semantic_version/base.py", line 86, in parse
    raise ValueError('Invalid version string: %r' % version_string)
ValueError: Invalid version string: '0.1'

One may also create a Version with named components:

>>> semantic_version.Version(major=0, minor=1, patch=2)
Version('0.1.2')

In that case, major, minor and patch are mandatory, and must be integers. prerelease and build, if provided, must be tuples of strings:

>>> semantic_version.Version(major=0, minor=1, patch=2, prerelease=('alpha', '2'))
Version('0.1.2-alpha.2')

Some user-supplied input might not match the semantic version scheme. For such cases, the Version.coerce method will try to convert any version-like string into a valid semver version:

>>> Version.coerce('0')
Version('0.0.0')
>>> Version.coerce('0.1.2.3.4')
Version('0.1.2+3.4')
>>> Version.coerce('0.1.2a3')
Version('0.1.2-a3')

Working with versions

Obviously, versions can be compared:

>>> semantic_version.Version('0.1.1') < semantic_version.Version('0.1.2')
True
>>> semantic_version.Version('0.1.1') > semantic_version.Version('0.1.1-alpha')
True
>>> semantic_version.Version('0.1.1') <= semantic_version.Version('0.1.1-alpha')
False

You can also get a new version that represents a bump in one of the version levels:

>>> v = semantic_version.Version('0.1.1+build')
>>> new_v = v.next_major()
>>> str(new_v)
'1.0.0'
>>> v = semantic_version.Version('1.1.1+build')
>>> new_v = v.next_minor()
>>> str(new_v)
'1.2.0'
>>> v = semantic_version.Version('1.1.1+build')
>>> new_v = v.next_patch()
>>> str(new_v)
'1.1.2'

Requirement specification

python-semanticversion provides a couple of ways to describe a range of accepted versions:

• The SimpleSpec class provides a simple, easily understood scheme --somewhat inspired from PyPI range notations;

• The NpmSpec class supports the whole NPM range specification scheme:

  >>> Version('0.1.2') in NpmSpec('0.1.0-alpha.2 .. 0.2.4')
  True
  >>> Version('0.1.2') in NpmSpec('>=0.1.1 <0.1.3 || 2.x')
  True
  >>> Version('2.3.4') in NpmSpec('>=0.1.1 <0.1.3 || 2.x')
  True
  

The SimpleSpec scheme

Basic usage is simply a comparator and a base version:

>>> s = SimpleSpec('>=0.1.1')  # At least 0.1.1
>>> s.match(Version('0.1.1'))
True
>>> s.match(Version('0.1.1-alpha1'))  # pre-release doesn't satisfy version spec
False
>>> s.match(Version('0.1.0'))
False

Combining specifications can be expressed as follows:

> pycon > >>> SimpleSpec('>=0.1.1,<0.3.0') >

Simpler test syntax is also available using the in keyword:

>>> s = SimpleSpec('==0.1.1')
>>> Version('0.1.1+git7ccc72') in s  # build variants are equivalent to full versions
True
>>> Version('0.1.1-alpha1') in s     # pre-release variants don't match the full version.
False
>>> Version('0.1.2') in s
False

Refer to the full documentation at for more details on the SimpleSpec scheme.

Using a specification

The SimpleSpec.filter method filters an iterable of Version:

>>> s = SimpleSpec('>=0.1.0,<0.4.0')
>>> versions = (Version('0.%d.0' % i) for i in range(6))
>>> for v in s.filter(versions):
...     print v
0.1.0
0.2.0
0.3.0

It is also possible to select the 'best' version from such iterables:

>>> s = SimpleSpec('>=0.1.0,<0.4.0')
>>> versions = (Version('0.%d.0' % i) for i in range(6))
>>> s.select(versions)
Version('0.3.0')

Contributing

In order to contribute to the source code:

• Open an issue on GitHub:

• Fork the repository and submit a pull request on GitHub

• Or send me a patch (mailto:raphael.barrois+semver@polytechnique.org)

When submitting patches or pull requests, you should respect the following rules:

• Coding conventions are based on 8
• The whole test suite must pass after adding the changes
• The test coverage for a new feature must be 100%
• New features and methods should be documented in the reference section and included in the changelog
• Include your name in the contributors section

# -*- encoding: utf-8 -*-
# Copyright (c) The python-semanticversion project