Sampo project - Reflex - Python examples

The ESO Recipe Flexible Execution Workbench

Instructions for Python usage in ESO Reflex

At present astronmers are widely using Python as a scripting languague and therefore it is important to get the flexibility and power of Python in use of ESO Reflex. This page includes instructions and examples with detailed description of the reflex.py Python module which is required for the usage in ESO Reflex.

Python interface of Reflex

The reflex.py Python module (download here) is the Python interface of Reflex. It is located under reflex/reflex-current/scripts/python. It contains the following four classes for reading parametres from stdin and printing output parameters from stdout back to java.

  • ReflexExit tells to Reflex we are exiting the Python script. When exiting the outputs are updated.

  • ReflexInput and ReflexOutput create the Reflex input and output ports with following three parameters:

    • name is an individual port identification name, e.g. dispCoeff

    • mimetype tells to Reflex the data type of the input/output, most common values are 'text/plain' and 'file/fits'

    • value is a value for the input port or the result for the output port, value can be in any type but it must be identical with mimetype

    These two classes contain also methods for setting and reading these parameters.

      • setMimeType(mimeType) sets the mime type of the port, mimeType is String

      • setName(name) sets the name of the port, name is String

      • setValue(value) sets the location of the port, value is e.g. "/home/tester/rectified_lamp_mxu.fits"

      • printValues() prints port name, mimeType and value

      • getName() returns port name

      • getMimeType() returns port mimeType

      • getValue() returns port value

  • ReflexQuery has three parameters

    • -q makes a Reflex query and displays Reflex ports with correct mimetypes and values

    • -d runs script with default values (god option with Python stand alone usage and for test purposes)

    • -help shows possible parameters

Python script editing window

In the figure below is the workflow pythonExample.xml located under reflex/reflex-current/examples.


Click on the Python processor Python_example, and the window below will open.


Edit a script

Edit the script by adding the row input2 = ReflexInput(type="'file/fits'",name="output2",value="test2.fits") under the row input1 = ReflexInput(type="'text/plain'",name="outputFilename",value="test.fits"). Press "Save script changes", and you will see in the figure below a new entry in the Input ports window.


The editor notes errors

Make on purpose an error to the scripts. In the example below the word BUG is written on a line. Try pressing "Save script changes", and you will get the message below.