The Python script below represents an advanced example of
 how to use the SED Importer CLI to create complex tasks.

 In this simple example, we create a set of sample input data files in
 ASCII format, to be converted by the SED Importer to a supported
 format for use in Iris; the script creates a separate SED Importer
 setup file for each.



 1) Create a directory for the input files. With your favorite text
    editor, create three text files: a_file.dat, b_file.dat, c_file.dat

 In each file create some data entries like the following:

 1.4e17      0.1e-12	0.01e-12
 1.5e17      0.2e-12	0.01e-12
 3.6e18      0.3e-13	0.01e-12
 3.7e18      0.4e-12	0.01e-12
 4.5e17      0.5e-12	0.01e-12

 Be sure that in the input files directory there are no other files,
 otherwise you will get errors from the Python script.



 2) Using a text editor, create the following Python script (be sure
    to create it outside the input file directory). Name it 
    import_sed_dir.py, for example.

    The code below is quite simple (most of it is just for strings
    manipulation) so you are encouraged to read it; the comments in
    the code should explain the most significant snippets. Remember to
    change the IMPORTER variable so that it points to the folder in
    which you have unzipped the Iris distribution.




-------- CODE BEGINS HERE ---------

#!/usr/bin/env python

import os
import sys  # We need to import some packages from the Python distribution

input_dir = sys.argv[1]   # The first command line argument is the directory with the input files
output_dir = sys.argv[2] # The second command line argument is the output directory

if not os.path.exists(output_dir): # If the output directory doesn't exist, create it
	print "Creating directory "+output_dir
	print
	os.mkdir(output_dir)

IMPORTER = '/home/user/downloads/iris-1.0-macosx-i386/SedImporter' # Edit this line to point to the SedImporter script in the Iris distribution

# The following dictionary contains all the Setup parameters that are common to all the files
common_params = {
	'XAxisColumnNumber' : '0',
	'XAxisQuantity' : 'FREQUENCY',
	'XAxisUnit' : 'HERTZ',
	'YAxisColumnNumber' : '1',
	'YAxisQuantity' : 'SPVFLUXDENSITY',
	'YAxisUnit' : 'FLUXDENSITYFREQ0',
	'errorType' : 'SymmetricColumn',
	'publisher' : 'OMAR',
	'symmetricErrorColumnNumber' : '2',
	'formatName' : 'ASCIITABLE',
}

# In the output directory create a setup file for each file in the input directory
for filename in os.listdir(input_dir):
	f = open(os.path.join(output_dir,filename+'.ini'), 'w')
	abspath = os.path.abspath(os.path.join(input_dir,filename))
	f.write('[Segment]\n') 				# This header is required in the Setup file to specify where the section begins
	for key, value in common_params.items():
		f.write(key+' = '+value+'\n')
	f.write('fileLocation = file://'+abspath+'\n') 	# Write the location of the current input file
	f.close() 

# execute SedImporter on each setup file
for file in [os.path.join(output_dir, f) for f in os.listdir(output_dir)]:
	if file.endswith('.ini'):
		output_file_name = os.path.split(file.replace('.ini', '.vot'))[1]
		output_file = os.path.join(output_dir, output_file_name)
		print
		print '***** Processing '+output_file+' *****'
		cmd = IMPORTER+' '+file+' '+output_file
		os.system(cmd) 				# Execute the SedImporter command line
		os.remove(file)				# Remove the temporary Setup file


-------- CODE ENDS HERE ---------


 3) To be sure the script can be executed, issue the following command  
    in a terminal window:

> chmod u+x  import_sed_dir.py


   The script takes exactly two arguments: the directory where the input
   files reside, and the directory into which it will write output
   files. If the output directory does not exist, it will create it.



 4) If you created the "files" directory as described above, you can
    launch the Python script as follows:

> ./import_sed_dir.py files outdir

  The output from the SED Importer will scroll on the terminal, so
  that you can spot errors if they occur. When the script is done, in
  the outdir directory you should find a list of files in VOTable
  format which you can load into Iris.