How to use the dxpy.describe function in dxpy

regions = set(regions) - set([curr_region])
    if len(regions) == 0:
        # there is nothing to do
        return

    app_supported_regions = set(COPY_FILE_APP.describe()['regionalOptions'].keys())
    if len(regions - app_supported_regions) > 0:
        print('Currently no support for the following region(s): [{regions}]'
              .format(regions=', '.join(regions - app_supported_regions)),
              file=sys.stderr)
        sys.exit(1)

    # Get information about the asset
    asset_properties = record.get_properties()
    asset_properties['cloned_from'] = record.get_id()
    asset_file_name = dxpy.describe(fid)['name']
    url = dxpy.DXFile(fid).get_download_url(preauthenticated=True,
                                            project=dxpy.DXFile.NO_PROJECT_HINT,
                                            duration=URL_DURATION)[0]

    # setup target folders
    region2projid = {}
    for region in regions:
        dest_proj = util.get_project(project_dict[region])
        dest_proj.new_folder(folder, parents=True)
        region2projid[region] = dest_proj.get_id()
    print(region2projid)

    # Fire off a clone process for each region
    # Wait for the cloning to complete
    for i in [1, 2, 3]:
        jobs = _clone_to_all_regions(region2projid, regions, asset_file_name, folder, url)

def analysis_files(analysis_id, keypair, server, assembly):
	analysis_id = analysis_id.strip()
	analysis = dxpy.describe(analysis_id)
	project = analysis.get('project')

	m = re.match('^(ENCSR[0-9]{3}[A-Z]{3}) Peaks',analysis['executableName'])
	if m:
		experiment_accession = m.group(1)
	else:
		logger.info("No accession in %s, skipping." %(analysis['executableName']))
		return

	experiment = common.encoded_get(urlparse.urljoin(server,'/experiments/%s' %(experiment_accession)), keypair)
	bams = get_rep_bams(experiment, keypair, server)
	rep1_bam = bams[0]['accession']
	rep2_bam = bams[1]['accession']

	common_metadata = {
		'assembly': assembly,

def flagstat_parse(dxlink):
    desc = dxpy.describe(dxlink)
    with dxpy.DXFile(desc['id'], mode='r') as flagstat_file:
        if not flagstat_file:
            return None
        flagstat_lines = flagstat_file.read().splitlines()

    qc_dict = {
        # values are regular expressions,
        # will be replaced with scores [hiq, lowq]
        'in_total': 'in total',
        'duplicates': 'duplicates',
        'mapped': 'mapped',
        'paired_in_sequencing': 'paired in sequencing',
        'read1': 'read1',
        'read2': 'read2',
        'properly_paired': 'properly paired',
        'with_self_mate_mapped': 'with itself and mate mapped',

def get_attachment(dxlink):
    desc = dxpy.describe(dxlink)
    filename = desc['name']
    mime_type = desc['media']
    if mime_type == 'text/plain' and not filename.endswith(".txt"):
        filename += ".txt"
    with dxpy.DXFile(desc['id'], mode='r') as stream:
        obj = {
            'download': filename,
            'type': mime_type,
            'href': 'data:%s;base64,%s' % (mime_type, b64encode(stream.read()))
        }
    return obj

def infer_pipeline_version(analysis):
    try:
        workflow = dxpy.describe(
            analysis['workflow']['id'], fields={'properties': True})
    except dxpy.exceptions.ResourceNotFound:
        analysis_date = analysis.get('created')
        # get the largest version number that was activated on a date before
        # this analysis was created
        pipeline_version = str(max([
            float(version) for version in VERSION_TIMES
            if VERSION_TIMES[version] < analysis_date])) or None
        logger.warning(
            "Workflow for %s is missing.  Inferred version %s"
            % (analysis.get('id'), pipeline_version))
    else:
        pipeline_version = workflow['properties'].get('pipeline_version')

    return pipeline_version or 'default'

def accession_analysis(analysis_id, keypair, server, assembly, dryrun, force):
	analysis_id = analysis_id.strip()
	analysis = dxpy.describe(analysis_id)
	project = analysis.get('project')

	m = re.match('^(ENCSR[0-9]{3}[A-Z]{3}) Peaks',analysis['executableName'])
	if m:
		experiment_accession = m.group(1)
		logger.info(experiment_accession)
	else:
		logger.info("No accession in %s, skipping." %(analysis['executableName']))
		return

	experiment = common.encoded_get(urlparse.urljoin(server,'/experiments/%s' %(experiment_accession)), keypair)
	bams = get_rep_bams(experiment, keypair, server)
	rep1_bam = bams[0]['accession']
	rep2_bam = bams[1]['accession']

	common_metadata = {

def describe(dxid_or_link):
        """Return json description for the given dxid"""
        key = json.dumps(dxid_or_link, sort_keys=True)
        if key not in DxTool._describe_result:
            DxTool._describe_result[key] = dxpy.describe(dxid_or_link)

        return DxTool._describe_result[key]
        #return _run_get_json('dx', 'describe', '--verbose', '--details', '--json', dxid)

def main():
    args = get_args()
    first_analysis = True

    for (i, analysis_id) in enumerate(args.infile):
        analysis_id = analysis_id.strip()
        try:
            analysis = dxpy.describe(analysis_id)
        except:
            print "Invalid analysis ID %s. Skipping." % (analysis_id)
            continue

        experiment_m = re.match('^(ENCSR[0-9]{3}[A-Z]{3})', analysis['name'])
        if not experiment_m:
            print "No accession in %s, skipping." % (analysis['name'])
            continue
            # print "Temporary hack"
            # experiment_accession = "ENCSR048KZD"
        else:
            experiment_accession = experiment_m.group(1)

        if args.pipeline:
            pipeline = args.pipeline
        elif analysis['executableName'] == 'histone_chip_seq':

else:
                logger.warning(
                    'fastqs with different or non-integer read_lengths: %s But fqcheck is False so ignoring'
                    % ([(fq.get('accession'), fq.get('read_length'))
                        for fq in fastqs]))
        except:
            raise
        mapped_read_length = int(next(l for l in native_lengths))
    else:
        mapped_read_length = int(crop_length)

    # here we get the actual DNAnexus file that was used as the reference
    # need to remain backwards-compatible with analyses that used output_JSON
    input_stage_output = \
        input_stage['output'].get('output_JSON') or input_stage['output']
    reference_file = dxpy.describe(input_stage_output['reference_tar'])

    # and construct the alias to find the corresponding file at ENCODEd
    reference_alias = "dnanexus:" + reference_file.get('id')

    logger.debug('looking for reference file with alias %s'
                 % (reference_alias))

    reference = common.encoded_get(
        urlparse.urljoin(server, 'files/%s' % (reference_alias)), keypair)
    assert reference, "Reference file %s not found on Portal" % (reference_alias) 
    logger.debug('found reference file %s' % (reference.get('accession')))

    bam_metadata = common.merge_dicts({
        'file_format': 'bam',
        'output_type': 'unfiltered alignments',
        'assembly': reference.get('assembly'),