Skip to content

ARROW-1028: [Python] Fix IPC docs per API changes #687

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wesm wants to merge 1 commit into from
Closed

ARROW-1028: [Python] Fix IPC docs per API changes #687

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
23 changes: 12 additions & 11 deletions python/doc/source/ipc.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -55,13 +55,13 @@ First, let's create a small record batch:
batch.num_columns

Now, we can begin writing a stream containing some number of these batches. For
this we use :class:`~pyarrow.BatchStreamWriter`, which can write to a writeable
this we use :class:`~pyarrow.RecordBatchStreamWriter`, which can write to a writeable
``NativeFile`` object or a writeable Python object:

.. ipython:: python

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

Here we used an in-memory Arrow buffer stream, but this could have been a
socket or some other IO sink.
Expand All @@ -80,11 +80,12 @@ particular stream. Now we can do:
buf.size

Now ``buf`` contains the complete stream as an in-memory byte buffer. We can
read such a stream with :class:`~pyarrow.BatchStreamReader`:
read such a stream with :class:`~pyarrow.RecordBatchStreamReader` or the
convenience function ``pyarrow.open_stream``:

.. ipython:: python

reader = pa.BatchStreamReader(buf)
reader = pa.open_stream(buf)
reader.schema

batches = [b for b in reader]
Expand All @@ -103,13 +104,13 @@ batches are also zero-copy and do not allocate any new memory on read.
Writing and Reading Random Access Files
---------------------------------------

The :class:`~pyarrow.BatchFileWriter` has the same API as
:class:`~pyarrow.BatchStreamWriter`:
The :class:`~pyarrow.RecordBatchFileWriter` has the same API as
:class:`~pyarrow.RecordBatchStreamWriter`:

.. ipython:: python

sink = pa.InMemoryOutputStream()
writer = pa.BatchFileWriter(sink, batch.schema)
writer = pa.RecordBatchFileWriter(sink, batch.schema)

for i in range(10):
writer.write_batch(batch)
Expand All @@ -118,14 +119,14 @@ The :class:`~pyarrow.BatchFileWriter` has the same API as
buf = sink.get_result()
buf.size

The difference between :class:`~pyarrow.BatchFileReader` and
:class:`~pyarrow.BatchStreamReader` is that the input source must have a
The difference between :class:`~pyarrow.RecordBatchFileReader` and
:class:`~pyarrow.RecordBatchStreamReader` is that the input source must have a
``seek`` method for random access. The stream reader only requires read
operations:
operations. We can also use the ``pyarrow.open_file`` method to open a file:

.. ipython:: python

reader = pa.BatchFileReader(buf)
reader = pa.open_file(buf)

Because we have access to the entire payload, we know the number of record
batches in the file, and can read any at random:
Expand Down