customspec.py 文件源码

def select_channel(
        self,
        versions: typing.Set[CustomVersion],
        update_channel: str = channel.STABLE
    ) -> typing.Union[CustomVersion, None]:
        """
        Selects the latest version, equals or higher than "channel"

        Args:
            versions: versions to select from
            update_channel: member of :class:`Channel`

        Returns: latest version or None

        """
        LOGGER.debug(f'selecting latest version amongst {len(versions)}; active channel: {str(channel)}')
        options = list(self.filter_channel(versions, update_channel))
        if options:
            latest = max(options)
            return latest
        LOGGER.debug('no version passed the test')
        return None