Common interface for obtaining the version of installed packages.

    CLI Example:

    .. code-block:: bash

        salt '*' pkg_resource.version vim
        salt '*' pkg_resource.version foo bar baz
        salt '*' pkg_resource.version 'python*'

def version(*names, **kwargs):
    '''
    Common interface for obtaining the version of installed packages.

    CLI Example:

    .. code-block:: bash

        salt '*' pkg_resource.version vim
        salt '*' pkg_resource.version foo bar baz
        salt '*' pkg_resource.version 'python*'
    '''
    ret = {}
    versions_as_list = \
        salt.utils.data.is_true(kwargs.pop('versions_as_list', False))
    pkg_glob = False
    if names:
        pkgs = __salt__['pkg.list_pkgs'](versions_as_list=True, **kwargs)
        for name in names:
            if '*' in name:
                pkg_glob = True
                for match in fnmatch.filter(pkgs, name):
                    ret[match] = pkgs.get(match, [])
            else:
                ret[name] = pkgs.get(name, [])
    if not versions_as_list:
        __salt__['pkg_resource.stringify'](ret)
    # Return a string if no globbing is used, and there is one item in the
    # return dict
    if len(ret) == 1 and not pkg_glob:
        try:
            return next(six.itervalues(ret))
        except StopIteration:
            return ''
    return ret