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 Unified File Read/Write Interface section.

Getting started

The Table class includes two methods, read() and write(), that make it possible to read from and write to files. A number of formats are automatically supported (see Built-In Table Readers/Writers) and new file formats and extensions can be registered with the Table class (see I/O Registry (astropy.io.registry)).

To use this interface, first import the Table class, then simply call the 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 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 Built-In Table Readers/Writers. This section also provides the full list of choices for the format argument.

Supported formats

The Unified File Read/Write Interface has built-in support for the following data file formats: