How to use the dataflows.dump_to_path function in dataflows

def test_example_5():
    from dataflows import Flow, set_type, dump_to_path

    f = Flow(
        country_population(),
        set_type('population', type='number', groupChar=','),
        dump_to_path('out/country_population')
    )
    _ = f.process()

# Now iterate on all resources
        resources = iter(package)
        beatles = next(resources)

        def f(row):
            row['is_guitarist'] = row['instrument'] == 'guitar'
            return row

        yield map(f, beatles)

    f = Flow(
        # Same one as above
        load('data/beatles.csv'),
        add_is_guitarist_column,
        dump_to_path('out/beatles_guitarists')
    )
    _ = f.process()

def run_flow(datetime_format=None):
        Flow(
            [{'today': str(_today), 'now': str(_now)}],
            set_type('today', type='date'),
            set_type('now', type='datetime', format=datetime_format),
            dump_to_path('out/dump_dates')
        ).process()

def test_save_load_dates():
    from dataflows import Flow, dump_to_path, load, set_type, printer
    import datetime

    Flow(
        [{'id': 1, 'ts': datetime.datetime.now()},
         {'id': 2, 'ts': datetime.datetime.now()}],
        set_type('ts', type='datetime', format='%Y-%m-%d/%H:%M:%S'),
        dump_to_path('out/test_save_load_dates')
    ).process()

    res, _, _ = Flow(
        load('out/test_save_load_dates/datapackage.json'),
        printer()
    ).results()

def test_load_from_env_var():
    import os
    from dataflows import load, dump_to_path

    Flow(
        [{'foo': 'bar'}],
        dump_to_path('out/load_from_env_var')
    ).process()

    os.environ['MY_DATAPACKAGE'] = 'out/load_from_env_var/datapackage.json'
    results, dp, _ = Flow(
        load('env://MY_DATAPACKAGE')
    ).results()

    assert len(dp.resources) == 1
    assert results == [[{'foo': 'bar'}]]

def main(package_url):
    jenkins_user_token = ckan_manager.get_jenkins_token('ckan-cloud-operator-jenkins-creds')
    package_url = package_url.replace('https://', 'https://{}:{}@'.format(*jenkins_user_token))
    stats_rows = []
    Flow(
        load(package_url),
        aggregate_stats(stats_rows),
        dump_to_path('data/aggregate_access_logs')
    ).process()
    Flow(
        (row for row in stats_rows),
        dump_to_path('data/aggregate_access_logs_stats'),
        printer()
    ).process()

return Flow(
        cluster_info(operator),
        update_resource(['res_1'], name='cluster-info', path='cluster-info.csv'),
        checkpoint(f'{prefix}-cluster-info'),
        ckan_cloud_instances(operator),
        update_resource(['res_2'], name='ckan-cloud-instances', path='ckan-cloud-instances.csv'),
    )


if __name__ == '__main__':
    prefix = os.environ['DATAPACKAGE_PREFIX']
    operator = os.environ.get('CKAN_CLOUD_OPERATOR_BIN', 'ckan-cloud-operator')
    Flow(
        main_flow(prefix, operator),
        printer(num_rows=1),
        dump_to_path(f'data/{prefix}/resources')
    ).process()

def list_instances():
    os.makedirs('data/list_instances', exist_ok=True)
    data = []
    Flow(
        (get_instance_row(instance) for instance in ckan_instance_manager.list_instances(full=True)),
        dump_to_json(data),
        dump_to_path('data/list_instances'),
        printer(num_rows=99999)
    ).process()
    with open('data/list_instances.json', 'w') as f:
        json.dump(data, f)