Source code for niftynet.utilities.versioning

# -*- coding: utf-8 -*-
from __future__ import absolute_import, print_function


def get_niftynet_version_string():
    """
    Return a user-visible string describing the name and product version

    This is a safe function that will never throw an exception
    """

    version_string = get_niftynet_version()
    if not version_string:
        version_string = "unknown"

    return "NiftyNet version " + version_string


def get_niftynet_version():
    """
    Return a user-visible string describing the product version

    This is a safe function that will never throw an exception
    """

    # Attempt to get the version string from the git repository
    try:
        version_buf, version_git, command_git = get_niftynet_git_version()
        version_string = version_git
    except:
        version_string = None

    # If we cannot get a git version, attempt to get a package version
    if not version_string:
        try:
            import pkg_resources
            version_string = pkg_resources.get_distribution("niftynet").version
        except:
            version_string = None

    return version_string


def get_niftynet_git_version():
    """
    Return a version string based on the git repository,
    conforming to PEP440
    """

    from subprocess import check_output

    # Describe the version relative to last tag
    command_git = ['git', 'describe', '--match', 'v[0-9]*']
    version_buf = check_output(command_git,
                               stderr=open('/dev/null', 'w')).rstrip()

    # Exclude the 'v' for PEP440 conformity, see
    # https://www.python.org/dev/peps/pep-0440/#public-version-identifiers
    version_buf = version_buf[1:]

    # Split the git describe output, as it may not be a tagged commit
    try:
        # converting if string returned as bytes object
        # (not Unicode str object)
        version_buf = version_buf.decode('utf-8')
    except AttributeError:
        pass

    try:
        tokens = version_buf.split('-')
    except TypeError:
        tokens = ['unknown token']

    if len(tokens) > 1:  # not a tagged commit
        # Format a developmental release identifier according to PEP440, see:
        # https://www.python.org/dev/peps/pep-0440/#developmental-releases
        version_git = '{}.dev{}'.format(tokens[0], tokens[1])
    elif len(tokens) == 1:  # tagged commit
        # Format a public version identifier according to PEP440, see:
        # https://www.python.org/dev/peps/pep-0440/#public-version-identifiers
        version_git = tokens[0]
    else:
        raise ValueError('Unexpected "git describe" output:'
                         '{}'.format(version_buf))

    return version_buf, version_git, command_git