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Last modified: December 2016

AHELP for CIAO 4.10


Context: scripting


Python is a dynamic object-oriented programming language used by CIAO


Python is a dynamic object-oriented programming language that can be used for many kinds of software development. It offers strong support for integration with other languages and tools and comes with extensive standard libraries. A list of key software features is available on the About Python webpage.

Refer to the Python Programming Language website for more information. Several web sites dedicated to using Python for Astronomical research exist, including AstroPython

Python in CIAO

The CIAO software offers Python as the user scripting environment. Python is distributed with CIAO, but users may opt to run their own custom installation instead; see "ahelp ciaorc" for information on how to change the Python version that is being used.

For more information, refer to the Scripting in CIAO webpages.


The following versions are provided with CIAO 4.9:

  • Python version 2.7.11 or 3.5.1 (as a beta release)
  • IPython version 4.2.0
  • NumPy version 1.11.0
  • six version 1.10.0

The Python version depends on the CIAO installation (i.e. a particular installation does not come with both Python versions). The --version flag can be used to determine the available version, such as

% python --version
Python 2.7.11


% python --version
Python 3.5.1

Changes in CIAO 4.9

Support for Python 3.5 is new and is provided as a beta release.

Last modified: December 2016
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