``pd.read_<file>`` and I/O APIs
=================================

A number of IO methods default to pandas. We have parallelized ``read_csv`` and
``read_parquet``, though many of the remaining methods can be relatively easily
parallelized. Some of the operations default to the pandas implementation, meaning it
will read in serially as a single, non-distributed DataFrame and distribute it.
Performance will be affected by this.

The following table is structured as follows: The first column contains the method name.
The second column is a flag for whether or not there is an implementation in Modin for
the method in the left column. ``Y`` stands for yes, ``N`` stands for no, ``P`` stands
for partial (meaning some parameters may not be supported yet), and ``D`` stands for
default to pandas.

.. note::
    Currently, the second column reflects implementation status for ``Ray`` and ``Dask`` engines. By default, support for a method
    in the ``Hdk`` engine could be treated as ``D`` unless ``Notes`` column contains additional information.

+--------------------+---------------------------------+----------------------------------------------------+
| IO method          | Modin Implementation? (Y/N/P/D) | Notes for Current implementation                   |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_csv`_        | Y                               | **Hdk**: ``P``, only basic cases and parameters    |
|                    |                                 | supported: ``filepath_or_buffer`` can be local file|
|                    |                                 | only, ``sep``, ``delimiter``,  ``header`` (partly) |
|                    |                                 | ``names``, ``usecols``, ``dtype``,                 |
|                    |                                 | ``true/false_values``, ``skiprows`` (partly)       |
|                    |                                 | ``skip_blank_lines`` (partly), ``parse_dates``     |
|                    |                                 | (partly), ``compression`` (inferred automatically, |
|                    |                                 | should not be specified), ``quotechar``,           |
|                    |                                 | ``escapechar``, ``doublequote``,                   |
|                    |                                 | ``delim_whitespace``                               |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_table`_      | Y                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_parquet`_    | Y                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_json`_       | P                               | Implemented for ``lines=True``                     |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_html`_       | D                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_clipboard`_  | D                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_excel`_      | D                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_hdf`_        | D                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_feather`_    | Y                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_msgpack`_    | D                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_stata`_      | D                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_sas`_        | D                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_pickle`_     | D                               | Experimental implementation:                       |
|                    |                                 | read_pickle_distributed                            |
+--------------------+---------------------------------+----------------------------------------------------+
| `read_sql`_        | Y                               |                                                    |
+--------------------+---------------------------------+----------------------------------------------------+

.. _`read_csv`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_csv.html#pandas.read_csv
.. _`read_table`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_table.html#pandas.read_table
.. _`read_parquet`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_parquet.html#pandas.read_parquet
.. _`read_json`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_json.html#pandas.read_json
.. _`read_html`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_html.html#pandas.read_html
.. _`read_clipboard`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_clipboard.html#pandas.read_clipboard
.. _`read_excel`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_excel.html#pandas.read_excel
.. _`read_hdf`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_hdf.html#pandas.read_hdf
.. _`read_feather`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_feather.html#pandas.read_feather
.. _`read_msgpack`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_msgpack.html#pandas.read_msgpack
.. _`read_stata`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_stata.html#pandas.read_stata
.. _`read_sas`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_sas.html#pandas.read_sas
.. _`read_pickle`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_pickle.html#pandas.read_pickle
.. _`read_sql`: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.read_sql.html#pandas.read_sql