def _import_rowids_file(args):
rows_csv_in, rowids_out, id_offset, id_stride, id_field = args
assert os.path.isfile(rows_csv_in)
with csv_reader(rows_csv_in) as reader:
header = reader.next()
if id_field is None:
basename = os.path.basename(rows_csv_in)
get_rowid = lambda i, row: '{}:{}'.format(basename, i)
else:
pos = header.index(id_field)
get_rowid = lambda i, row: row[pos]
with csv_writer(rowids_out) as writer:
for i, row in enumerate(reader):
writer.writerow((id_offset + id_stride * i, get_rowid(i, row)))
def _import_rowids_file(args):
rows_csv_in, rowids_out, id_offset, id_stride, id_field = args
assert os.path.isfile(rows_csv_in)
with csv_reader(rows_csv_in) as reader:
header = reader.next()
if id_field is None:
basename = os.path.basename(rows_csv_in)
get_rowid = lambda i, row: '{}:{}'.format(basename, i)
else:
pos = header.index(id_field)
get_rowid = lambda i, row: row[pos]
with csv_writer(rowids_out) as writer:
for i, row in enumerate(reader):
writer.writerow((id_offset + id_stride * i, get_rowid(i, row)))
def export_rows(encoding_in, rows_in, rows_csv_out, chunk_size=1000000):
'''
Export rows from gzipped-protobuf-stream to directory-of-gzipped-csv-files.
'''
rows_csv_out = os.path.abspath(rows_csv_out)
if rows_csv_out == os.getcwd():
raise LoomError('Cannot export_rows to working directory')
for ext in ['.csv', '.gz', '.bz2']:
if rows_csv_out.endswith(ext):
raise LoomError(
'Expected rows_csv_out to be a dirname, actual'.format(
rows_csv_out))
if not (chunk_size > 0):
raise LoomError('Invalid chunk_size {}, must be positive'.format(
chunk_size))
encoders = json_load(encoding_in)
fields = [loom.schema.MODEL_TO_DATATYPE[e['model']] for e in encoders]
decoders = [load_decoder(e) for e in encoders]
header = ['_id'] + [e['name'] for e in encoders]
if os.path.exists(rows_csv_out):
shutil.rmtree(rows_csv_out)
os.makedirs(rows_csv_out)
row_count = sum(1 for _ in protobuf_stream_load(rows_in))
rows = loom.cFormat.row_stream_load(rows_in)
chunk_count = (row_count + chunk_size - 1) / chunk_size
chunks = sorted(
os.path.join(rows_csv_out, 'rows.{}.csv.gz'.format(i))
for i in xrange(chunk_count)
)
with ExitStack() as stack:
with_ = stack.enter_context
writers = [with_(csv_writer(f)) for f in chunks]
for writer in writers:
writer.writerow(header)
for row, writer in izip(rows, cycle(writers)):
data = row.iter_data()
schema = izip(data['observed'], fields, decoders)
csv_row = [row.id]
for observed, field, decode in schema:
csv_row.append(decode(data[field].next()) if observed else '')
writer.writerow(csv_row)
