version.py

# Copyright: 2018, Matt Martz <matt@sivel.net>
# Simplified BSD License (see licenses/simplified_bsd.txt or https://opensource.org/licenses/BSD-2-Clause )

from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

__all__ = ['Version', 'parse']

try:
    from packaging.version import LegacyVersion, Version as Pep440Version, parse
    HAS_PACKAGING = True
except ImportError:
    try:
        from pip._vendor.packaging.version import LegacyVersion, Version as Pep440Version, parse
        HAS_PACKAGING = True
    except ImportError:
        from distutils.version import LooseVersion, StrictVersion
        HAS_PACKAGING = False


if not HAS_PACKAGING:
    def parse(version):
        try:
            return StrictVersion(version)
        except ValueError:
            return LooseVersion(version)


class Version:
    def __new__(cls, version, strict=False):
        if HAS_PACKAGING:
            if strict:
                return Pep440Version(version)
            else:
                return LegacyVersion(version)
        else:
            if strict:
                return StrictVersion(version)
            else:
                return LooseVersion(version)