| .. doctest-skip-all |
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| .. _read_write_tables: |
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|
| Reading and writing Table objects |
| *********************************** |
|
|
| Astropy provides a unified interface for reading and writing data |
| in different formats. For many common cases this will |
| simplify the process of file I/O and reduce the need to master |
| the separate details of all 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`). |
|
|
| To use this interface, first import the :class:`~astropy.table.Table` class, then |
| simply 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 catalogues 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") |
|
|
| 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` |
|
|
