writing some arrow test data

write_test_arrow.py

import pyarrow as pa

v = pa.array([1,2,3,4])

batch = pa.RecordBatch.from_arrays([v], ["this_is_the_column_name"])

sink = pa.BufferOutputStream()

writer = pa.RecordBatchStreamWriter(sink, batch.schema)

writer.write_batch(batch)
writer.close()

buf = sink.getvalue()

b = buf.to_pybytes()  # this is the buffer containing the full streaming format

# schema_buffer = batch.schema.serialize().to_pybytes()

f = open("testdata1.dat", "wb")
f.write(b)
f.close()