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.. doctest-skip-all
.. _read_write_tables:
Reading and Writing Table Objects
*********************************
``astropy`` provides a unified interface for reading and writing data in
different formats. For many common cases this will streamline the process of
file I/O and reduce the need to learn the separate details of all of the I/O
packages within ``astropy``. For details and examples of using this interface
see the :ref:`table_io` section.
Getting Started
===============
The :class:`~astropy.table.Table` class includes two methods,
:meth:`~astropy.table.Table.read` and :meth:`~astropy.table.Table.write`, that
make it possible to read from and write to files. A number of formats are
automatically supported (see :ref:`built_in_readers_writers`) and new file
formats and extensions can be registered with the :class:`~astropy.table.Table`
class (see :ref:`io_registry`).
.. EXAMPLE START: Reading and Writing Table Objects
To use this interface, first import the :class:`~astropy.table.Table` class,
then call the :class:`~astropy.table.Table` :meth:`~astropy.table.Table.read`
method with the name of the file and the file format, for instance
``'ascii.daophot'``::
>>> from astropy.table import Table
>>> t = Table.read('photometry.dat', format='ascii.daophot')
It is possible to load tables directly from the Internet using URLs. For
example, download tables from `VizieR catalogs <https://vizier.u-strasbg.fr/>`_
in CDS format (``'ascii.cds'``)::
>>> t = Table.read("ftp://cdsarc.u-strasbg.fr/pub/cats/VII/253/snrs.dat",
... readme="ftp://cdsarc.u-strasbg.fr/pub/cats/VII/253/ReadMe",
... format="ascii.cds")
.. EXAMPLE END
For certain file formats, the format can be automatically detected, for
example from the filename extension::
>>> t = Table.read('table.tex')
Similarly, for writing, the format can be explicitly specified::
>>> t.write(filename, format='latex')
As for the :meth:`~astropy.table.Table.read` method, the format may
be automatically identified in some cases.
Any additional arguments specified will depend on the format. For examples of
this see the section :ref:`built_in_readers_writers`. This section also
provides the full list of choices for the ``format`` argument.
Supported Formats
=================
The :ref:`table_io` has built-in support for the following data file formats:
* :ref:`table_io_ascii`
* :ref:`table_io_hdf5`
* :ref:`table_io_fits`
* :ref:`table_io_votable`
* :ref:`table_io_parquet`
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