Intro to astrotools

The BDNYC Python module astrotools is now up and running for all to use and edit. This module is intended to be a collection of useful pieces of code for our everyday data handling needs. So far, astrotools is useful to handle fits files and spectral data. Additions to astrotools are welcome.

Let me clear out some relevant Python concepts. A module is simply a set of functional pieces of code. These pieces can be either functions or classes, among other things. A function is a code that executes an action, for example “make me a sandwich”. A class is a code that creates an object with specific characteristics and it allows you to handle this object very effectively. For the example above, you can have a class to create the person that will make the sandwich, a class to create a slice of mortadella, and a class to create mayonnaise. Of course, you can have functions that make no use of classes. More on that in a future post.

Where to find astrotools and how to install it

The module astrotools is available at as Make sure that you download it into one of your Python folders in sys.path, which are the folders where Python looks for modules whenever you invoke one in your Python session. If you have no idea what I am referring to, please read this piece of Python documentation.

How to use astrotools

Now you are ready to invoke astrotools into your Python session. Type:

“import astrotools”

That’s it! You are ready to use astrootols functions and classes. For example, if you want to use the function that gets spectral data from a fits file, type:

“x = astrotools.read_spec(filename)”

and x will hold the output of the read_spec function. To learn about the functions and classes in astrotools, visit

By convention, modules are invoked using a nickname, if only to make typing easier. I
suggest the nickname “at”. Then, import astrotools by typing:

“import astrotools as at”

To use it, type:

“x = at.read_spec(filename)”

In later posts I will describe in greater detail some important Python concepts as well as some guidelines to follow when editing astrotools.

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