 
Basics, Building SPICE Applications (Python)
===========================================================================
 
   May 21, 2018
 
 
Note About HTML Links
--------------------------------------------------------
 
   The HTML version of this lesson contains links pointing to various HTML
   documents provided with the Toolkit. All of these links are relative
   and, in order to function, require this document to be in a certain
   location in the Toolkit HTML documentation directory tree.
 
   In order for the links to be resolved, if not done already by installing
   the lessons package under the Toolkit's ``doc/html'' directory, create a
   subdirectory called ``lessons'' under the ``doc/html'' directory of the
   ``cspice/'' tree and copy this document to that subdirectory before
   loading it into a Web browser.
 
 
Environment Set-up
--------------------------------------------------------
 
   SpiceyPy is currently supported on Mac, Linux, and Windows systems.
 
   In order to install SpiceyPy, using pip, first install the following
   required packages:
 
                 $ pip install six
                 $ pip install numpy
                 $ pip install spiceypy
 
   Python2 users would need to use the future package in order to get the
   same behavior from the Python3 input function in Python2. This package
   is installed by running:
 
                 $ pip install future
 
   Using anaconda, miniconda or conda:
 
         $ conda install -c https://conda.anaconda.org/andrewannex spiceypy
 
 
Confirm that Python can access SpiceyPy
--------------------------------------------------------
 
   Run pip list in order to get a list of the third party libraries that
   are currently available to your Python installation:
 
         $ pip list --format=columns
         Package    Version
         ---------- -------
         pip        9.0.1
         numpy      1.13.3
         setuptools 36.5.0
         six        1.11.0
         ...
         spicepy    2.1.1
         ...
 
 
A simple example program
--------------------------------------------------------
 
   This script calls the spiceypy function 'tkvrsn' and outputs the return
   value.
 
              File tkvrsn.py
 
                 from __future__ import print_function
                 import spiceypy
 
                 def print_ver():
                         """Prints the TOOLKIT version
                         """
                         print(spiceypy.tkvrsn('TOOLKIT'))
 
                 if __name__ == '__main__':
                         print_ver()
 
   From the command line, execute the function:
 
              $ python tkvrsn.py
              CSPICE_N0066
 
   From Python, execute the function:
 
              $ python
              >>> import tkvrsn
              >>> tkvrsn.print_ver()
              CSPICE_N0066
 
 
SpiceyPy Documentation
--------------------------------------------------------
 
   The current version of SpiceyPy does not provide extensive
   documentation, but there are several ways to navigate your way through
   the Python version of the toolkit. One simple way is to use the standard
   Python mechanisms. All interfaces implemented in SpiceyPy can be listed
   using the standard built-in function dir(), which returns an
   alphabetized list of names comprising (among) other things, the API
   names. If you need to get additional information about an API
   parameters, the standard built-in function help() could be used:
 
      >>> import spiceypy
      >>> help(spiceypy.)
 
   which produces
 
      Help on function tkvrsn in module spiceypy.spiceypy:
 
      tkvrsn(item)
          Given an item such as the Toolkit or an entry point name, return
          the latest version string.
 
          http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/tkvrsn_c.
      html
 
          :param item: Item for which a version string is desired.
          :type item: str
          :return: the latest version string.
          :rtype: str
 
   As indicated in the help on the function, the complete documentation is
   available on the CSPICE toolkit version. Therefore it is recommended to
   have the CSPICE toolkit version installed locally in order to access its
   documentation offline.
 
