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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def import_from_xml(xml, edx_video_id, resource_fs, static_dir, external_transcripts=dict(), course_id=None):
 """ Imports data from a video_asset element about the given video_id. If the edx_video_id already exists, then no changes are made. If an unknown profile is referenced by an encoded video, that encoding will be ignored. Arguments: xml (Element):
 An lxml video_asset element containing import data edx_video_id (str):
 val video id resource_fs (OSFS):
 Import file system. static_dir (str):
 The Directory to retrieve transcript file. external_transcripts (dict):
 A dict containing the list of names of the external transcripts. Example: { 'en': ['The_Flash.srt', 'Harry_Potter.srt'], 'es': ['Green_Arrow.srt'] } course_id (str):
 The ID of a course to associate the video with Raises: ValCannotCreateError: if there is an error importing the video Returns: edx_video_id (str):
 val video id. """

    if xml.tag != 'video_asset':
        raise ValCannotCreateError('Invalid XML')

    # If video with edx_video_id already exists, associate it with the given course_id.
    try:
        if not edx_video_id:
            raise Video.DoesNotExist

        video = Video.objects.get(edx_video_id=edx_video_id)
        logger.info(
            "edx_video_id '%s' present in course '%s' not imported because it exists in VAL.",
            edx_video_id,
            course_id,
        )

        # We don't want to link an existing video to course if its an external video.
        # External videos do not have any playback profiles associated, these are just to track video
        # transcripts for those video components who do not use edx hosted videos for playback.
        if course_id and video.status != EXTERNAL_VIDEO_STATUS:
            course_video, __ = CourseVideo.get_or_create_with_validation(video=video, course_id=course_id)

            image_file_name = xml.get('image', '').strip()
            if image_file_name:
                VideoImage.create_or_update(course_video, image_file_name)

        return edx_video_id
    except ValidationError as err:
        logger.exception(err.message)
        raise ValCannotCreateError(err.message_dict)
    except Video.DoesNotExist:
        pass

    if edx_video_id:
        # Video with edx_video_id did not exist, so create one from xml data.
        data = {
            'edx_video_id': edx_video_id,
            'client_video_id': xml.get('client_video_id'),
            'duration': xml.get('duration'),
            'status': 'imported',
            'encoded_videos': [],
            'courses': [{course_id: xml.get('image')}] if course_id else [],
        }
        for encoded_video_el in xml.iterfind('encoded_video'):
            profile_name = encoded_video_el.get('profile')
            try:
                Profile.objects.get(profile_name=profile_name)
            except Profile.DoesNotExist:
                logger.info(
                    "Imported edx_video_id '%s' contains unknown profile '%s'.",
                    edx_video_id,
                    profile_name
                )
                continue
            data['encoded_videos'].append({
                'profile': profile_name,
                'url': encoded_video_el.get('url'),
                'file_size': encoded_video_el.get('file_size'),
                'bitrate': encoded_video_el.get('bitrate'),
            })

        if not data['encoded_videos']:
            # Video's status does not get included in video xml at the time of export. So, at this point,
            # we cannot tell from xml that whether a video had an external status. But if encoded videos
            # are not set, the chances are, the video was an external one, in which case, we will not link
            # it to the course(s). Even if the video wasn't an external one and it is having 0 encodes in
            # xml, it does not have a side effect if not linked to a course, since the video was already
            # non-playable.
            data['status'] = EXTERNAL_VIDEO_STATUS
            data['courses'] = []

        # Create external video if no edx_video_id.
        edx_video_id = create_video(data)
    else:
        edx_video_id = create_external_video('External Video')

    create_transcript_objects(xml, edx_video_id, resource_fs, static_dir, external_transcripts)
    return edx_video_id