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deb-python-semantic-version/docs/reference.rst
2016-03-07 13:15:14 +01:00

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Reference
=========
.. module:: semantic_version
Module-level functions
----------------------
.. function:: compare(v1, v2)
Compare two version strings, and return a result similar to that of :func:`cmp`::
>>> compare('0.1.1', '0.1.2')
-1
>>> compare('0.1.1', '0.1.1')
0
>>> compare('0.1.1', '0.1.1-alpha')
1
:param str v1: The first version to compare
:param str v2: The second version to compare
:raises: :exc:`ValueError`, if any version string is invalid
:rtype: ``int``, -1 / 0 / 1 as for a :func:`cmp` comparison;
``NotImplemented`` if versions only differ by build metadata
.. warning:: Since build metadata has no ordering,
``compare(Version('0.1.1'), Version('0.1.1+3'))`` returns ``NotImplemented``
.. function:: match(spec, version)
Check whether a version string matches a specification string::
>>> match('>=0.1.1', '0.1.2')
True
>>> match('>=0.1.1', '0.1.1-alpha')
False
>>> match('~0.1.1', '0.1.1-alpha')
True
:param str spec: The specification to use, as a string
:param str version: The version string to test against the spec
:raises: :exc:`ValueError`, if the ``spec`` or the ``version`` is invalid
:rtype: ``bool``
.. function:: validate(version)
Check whether a version string complies with the `SemVer`_ rules.
.. code-block:: pycon
>>> semantic_version.validate('1.1.1')
True
>>> semantic_version.validate('1.2.3a4')
False
:param str version: The version string to validate
:rtype: ``bool``
Representing a version (the Version class)
------------------------------------------
.. class:: Version(version_string[, partial=False])
Object representation of a `SemVer`_-compliant version.
Constructed from a textual version string::
>>> Version('1.1.1')
Version('1.1.1')
>>> str(Version('1.1.1'))
'1.1.1'
.. rubric:: Attributes
.. attribute:: partial
``bool``, whether this is a 'partial' or a complete version number.
Partial version number may lack :attr:`minor` or :attr:`patch` version numbers.
.. attribute:: major
``int``, the major version number
.. attribute:: minor
``int``, the minor version number.
May be ``None`` for a :attr:`partial` version number in a ``<major>`` format.
.. attribute:: patch
``int``, the patch version number.
May be ``None`` for a :attr:`partial` version number in a ``<major>`` or ``<major>.<minor>`` format.
.. attribute:: prerelease
``tuple`` of ``strings``, the prerelease component.
It contains the various dot-separated identifiers in the prerelease component.
May be ``None`` for a :attr:`partial` version number in a ``<major>``, ``<major>.<minor>`` or ``<major>.<minor>.<patch>`` format.
.. attribute:: build
``tuple`` of ``strings``, the build metadata.
It contains the various dot-separated identifiers in the build metadata.
May be ``None`` for a :attr:`partial` version number in a ``<major>``, ``<major>.<minor>``,
``<major>.<minor>.<patch>`` or ``<major>.<minor>.<patch>-<prerelease>`` format.
.. rubric:: Methods
.. method:: __iter__(self)
Iterates over the version components (:attr:`major`, :attr:`minor`,
:attr:`patch`, :attr:`prerelease`, :attr:`build`)::
>>> list(Version('0.1.1'))
[0, 1, 1, [], []]
.. note:: This may pose some subtle bugs when iterating over a single version
while expecting an iterable of versions -- similar to::
>>> list('abc')
['a', 'b', 'c']
>>> list(('abc',))
['abc']
.. method:: __cmp__(self, other)
Provides comparison methods with other :class:`Version` objects.
The rules are:
- For non-:attr:`partial` versions, compare using the `SemVer`_ scheme
- If any compared object is :attr:`partial`:
- Begin comparison using the `SemVer`_ scheme
- If a component (:attr:`minor`, :attr:`patch`, :attr:`prerelease` or :attr:`build`)
was absent from the :attr:`partial` :class:`Version` -- represented with :obj:`None`
--, consider both versions equal.
For instance, ``Version('1.0', partial=True)`` means "any version beginning in ``1.0``".
``Version('1.0.1-alpha', partial=True)`` means "The ``1.0.1-alpha`` version or any
any release differing only in build metadata": ``1.0.1-alpha+build3`` matches, ``1.0.1-alpha.2`` doesn't.
Examples::
>>> Version('1.0', partial=True) == Version('1.0.1')
True
>>> Version('1.0.1-rc1.1') == Version('1.0.1-rc1', partial=True)
False
>>> Version('1.0.1-rc1+build345') == Version('1.0.1-rc1')
False
>>> Version('1.0.1-rc1+build345') == Version('1.0.1-rc1', partial=True)
True
.. method:: __str__(self)
Returns the standard text representation of the version::
>>> v = Version('0.1.1-rc2+build4.4')
>>> v
Version('0.1.1-rc2+build4.4')
>>> str(v)
'0.1.1-rc2+build4.4'
.. method:: __hash__(self)
Provides a hash based solely on the components.
Allows using a :class:`Version` as a dictionary key.
.. note:: A fully qualified :attr:`partial` :class:`Version`
(up to the :attr:`build` component) will hash the same as the
equally qualified, non-:attr:`partial` :class:`Version`::
>>> hash(Version('1.0.1+build4')) == hash(Version('1.0.1+build4', partial=True))
True
.. rubric:: Class methods
.. classmethod:: parse(cls, version_string[, partial=False])
Parse a version string into a ``(major, minor, patch, prerelease, build)`` tuple.
:param str version_string: The version string to parse
:param bool partial: Whether this should be considered a :attr:`partial` version
:raises: :exc:`ValueError`, if the :attr:`version_string` is invalid.
:rtype: (major, minor, patch, prerelease, build)
.. classmethod:: coerce(cls, version_string[, partial=False])
Try to convert an arbitrary version string into a :class:`Version` instance.
Rules are:
- If no minor or patch component, and :attr:`partial` is :obj:`False`,
replace them with zeroes
- Any character outside of ``a-zA-Z0-9.+-`` is replaced with a ``-``
- If more than 3 dot-separated numerical components, everything from the
fourth component belongs to the :attr:`build` part
- Any extra ``+`` in the :attr:`build` part will be replaced with dots
Examples:
.. code-block:: pycon
>>> Version.coerce('02')
Version('2.0.0')
>>> Version.coerce('1.2.3.4')
Version('1.2.3+4')
>>> Version.coerce('1.2.3.4beta2')
Version('1.2.3+4beta2')
>>> Version.coerce('1.2.3.4.5_6/7+8+9+10')
Version('1.2.3+4.5-6-7.8.9.10')
:param str version_string: The version string to coerce
:param bool partial: Whether to allow generating a :attr:`partial` version
:raises: :exc:`ValueError`, if the :attr:`version_string` is invalid.
:rtype: :class:`Version`
Version specifications (the Spec class)
---------------------------------------
Version specifications describe a 'range' of accepted versions:
older than, equal, similar to, …
The main issue with representing version specifications is that the usual syntax
does not map well onto `SemVer`_ precedence rules:
* A specification of ``<1.3.4`` is not expected to allow ``1.3.4-rc2``, but strict `SemVer`_ comparisons allow it ;
prereleases has the issue of excluding ``1.3.3+build3`` ;
* It may be necessary to exclude either all variations on a patch-level release
(``!=1.3.3``) or specifically one build-level release (``1.3.3-build.434``).
In order to have version specification behave naturally, the rules are the following:
* If no pre-release number was included in the specification, pre-release numbers
are ignored when deciding whether a version satisfies a specification.
* If no build metadata was included in the specification, build metadata is ignored
when deciding whether a version satisfies a specification.
This means that::
>>> Version('1.1.1-rc1') in Spec('<1.1.1')
False
>>> Version('1.1.1-rc1') in Spec('<1.1.1-rc4')
True
>>> Version('1.1.1-rc1+build4') in Spec('<=1.1.1-rc1')
True
>>> Version('1.1.1-rc1+build4') in Spec('==1.1.1-rc1+build2')
False
.. note:: python-semanticversion also accepts ``"*"`` as a version spec,
that matches all (valid) version strings.
.. note:: python-semanticversion supports PyPI-style `compatible release clauses`_:
* ``~=2.2`` means "Any release between 2.2.0 and 3.0.0"
* ``~=1.4.5`` means "Any release between 1.4.5 and 1.5.0"
.. note:: python-semanticversion includes support for NPM-style specs:
* ``~1.2.3`` means "Any release between 1.2.3 and 1.3.0"
* ``^1.3.4`` means "Any release between 1.3.4 and 2.0.0"
In order to force matches to *strictly* compare version numbers, these additional
rules apply:
* Setting a pre-release separator without a pre-release identifier (``<=1.1.1-``)
forces match to take into account pre-release version::
>>> Version('1.1.1-rc1') in Spec('<1.1.1')
False
>>> Version('1.1.1-rc1') in Spec('<1.1.1-')
True
* Setting a build metadata separator without build metadata (``<=1.1.1+``)
forces matches "up to the build metadata"; use this to include/exclude a
release lacking build metadata while excluding/including all other builds
of that release
>>> Version('1.1.1') in Spec('==1.1.1+')
True
>>> Version('1.1.1+2') in Spec('==1.1.1+')
False
.. warning:: As stated in the `SemVer`_ specification, the ordering of build metadata is *undefined*.
Thus, a :class:`Spec` string can only mention build metadata to include or exclude a specific version:
* ``==1.1.1+b1234`` includes this specific build
* ``!=1.1.1+b1234`` excludes it (but would match ``1.1.1+b1235``
* ``<1.1.1+b1`` is invalid
.. class:: Spec(spec_string[, spec_string[, ...]])
Stores a list of :class:`SpecItem` and matches any :class:`Version` against all
contained :class:`specs <SpecItem>`.
It is built from a comma-separated list of version specifications::
>>> Spec('>=1.0.0,<1.2.0,!=1.1.4')
<Spec: (
<SpecItem: >= Version('1.0.0', partial=True)>,
<SpecItem: < Version('1.2.0', partial=True)>,
<SpecItem: != Version('1.1.4', partial=True)>
)>
Version specifications may also be passed in separated arguments::
>>> Spec('>=1.0.0', '<1.2.0', '!=1.1.4,!=1.1.13')
<Spec: (
<SpecItem: >= Version('1.0.0', partial=True)>,
<SpecItem: < Version('1.2.0', partial=True)>,
<SpecItem: != Version('1.1.4', partial=True)>,
<SpecItem: != Version('1.1.13', partial=True)>,
)>
.. rubric:: Attributes
.. attribute:: specs
Tuple of :class:`SpecItem`, the included specifications.
.. rubric:: Methods
.. method:: match(self, version)
Test whether a given :class:`Version` matches all included :class:`SpecItem`::
>>> Spec('>=1.1.0,<1.1.2').match(Version('1.1.1'))
True
:param version: The version to test against the specs
:type version: :class:`Version`
:rtype: ``bool``
.. method:: filter(self, versions)
Extract all compatible :class:`versions <Version>` from an iterable of
:class:`Version` objects.
:param versions: The versions to filter
:type versions: iterable of :class:`Version`
:yield: :class:`Version`
.. method:: select(self, versions)
Select the highest compatible version from an iterable of :class:`Version`
objects.
.. sourcecode:: pycon
>>> s = Spec('>=0.1.0')
>>> s.select([])
None
>>> s.select([Version('0.1.0'), Version('0.1.3'), Version('0.1.1')])
Version('0.1.3')
:param versions: The versions to filter
:type versions: iterable of :class:`Version`
:rtype: The highest compatible :class:`Version` if at least one of the
given versions is compatible; :class:`None` otherwise.
.. method:: __contains__(self, version)
Alias of the :func:`match` method;
allows the use of the ``version in speclist`` syntax::
>>> Version('1.1.1-alpha') in Spec('>=1.1.0,<1.1.1')
True
.. method:: __str__(self)
Converting a :class:`Spec` returns the initial description string::
>>> str(Spec('>=0.1.1,!=0.1.2'))
'>=0.1.1,!=0.1.2'
.. method:: __iter__(self)
Returns an iterator over the contained specs::
>>> for spec in Spec('>=0.1.1,!=0.1.2'):
... print spec
>=0.1.1
!=0.1.2
.. method:: __hash__(self)
Provides a hash based solely on the hash of contained specs.
Allows using a :class:`Spec` as a dictionary key.
.. rubric:: Class methods
.. classmethod:: parse(self, specs_string)
Retrieve a ``(*specs)`` tuple from a string.
:param str requirement_string: The textual description of the specifications
:raises: :exc:`ValueError`: if the ``requirement_string`` is invalid.
:rtype: ``(*spec)`` tuple
.. class:: SpecItem(spec_string)
.. note:: This class belong to the private python-semanticversion API.
Stores a version specification, defined from a string::
>>> SpecItem('>=0.1.1')
<SpecItem: >= Version('0.1.1', partial=True)>
This allows to test :class:`Version` objects against the :class:`SpecItem`::
>>> SpecItem('>=0.1.1').match(Version('0.1.1-rc1')) # pre-release satisfy conditions
True
>>> Version('0.1.1+build2') in SpecItem('>=0.1.1') # build metadata is ignored when checking for precedence
True
>>>
>>> # Use the '-' marker to include the pre-release component in checks
>>> SpecItem('>=0.1.1-').match(Version('0.1.1-rc1')
False
>>> # Use the '+' marker to include the build metadata in checks
>>> SpecItem('==0.1.1+').match(Version('0.1.1+b1234')
False
>>>
.. rubric:: Attributes
.. attribute:: kind
One of :data:`KIND_LT`, :data:`KIND_LTE`, :data:`KIND_EQUAL`, :data:`KIND_GTE`,
:data:`KIND_GT` and :data:`KIND_NEQ`.
.. attribute:: spec
:class:`Version` in the :class:`SpecItem` description.
It is alway a :attr:`~Version.partial` :class:`Version`.
.. rubric:: Class methods
.. classmethod:: parse(cls, requirement_string)
Retrieve a ``(kind, version)`` tuple from a string.
:param str requirement_string: The textual description of the specification
:raises: :exc:`ValueError`: if the ``requirement_string`` is invalid.
:rtype: (``kind``, ``version``) tuple
.. rubric:: Methods
.. method:: match(self, version)
Test whether a given :class:`Version` matches this :class:`SpecItem`::
>>> SpecItem('>=0.1.1').match(Version('0.1.1-alpha'))
True
>>> SpecItem('>=0.1.1-').match(Version('0.1.1-alpha'))
False
:param version: The version to test against the spec
:type version: :class:`Version`
:rtype: ``bool``
.. method:: __str__(self)
Converting a :class:`SpecItem` to a string returns the initial description string::
>>> str(SpecItem('>=0.1.1'))
'>=0.1.1'
.. method:: __hash__(self)
Provides a hash based solely on the current kind and the specified version.
Allows using a :class:`SpecItem` as a dictionary key.
.. rubric:: Class attributes
.. data:: KIND_LT
The kind of 'Less than' specifications::
>>> Version('1.0.0-alpha') in Spec('<1.0.0')
False
.. data:: KIND_LTE
The kind of 'Less or equal to' specifications::
>>> Version('1.0.0-alpha1+build999') in Spec('<=1.0.0-alpha1')
True
.. data:: KIND_EQUAL
The kind of 'equal to' specifications::
>>> Version('1.0.0+build3.3') in Spec('==1.0.0')
True
.. data:: KIND_GTE
The kind of 'Greater or equal to' specifications::
>>> Version('1.0.0') in Spec('>=1.0.0')
True
.. data:: KIND_GT
The kind of 'Greater than' specifications::
>>> Version('1.0.0+build667') in Spec('>1.0.1')
False
.. data:: KIND_NEQ
The kind of 'Not equal to' specifications::
>>> Version('1.0.1') in Spec('!=1.0.1')
False
The kind of 'Almost equal to' specifications
.. _SemVer: http://semver.org/
.. _`compatible release clauses`: https://www.python.org/dev/peps/pep-0440/#compatible-release