Python is a powerful, object-oriented open-source scripting language that is in use all over the world. Within Chameleon, you can write Python scripts that allow you to manipulate HL7 message data.

You can use Python to:

• Manipulate incoming HL7 messages to convert them to a format that your application can process;
• Manipulate outgoing HL7 messages after your application generates them, but before it sends them out;
• Modify individual data fields in HL7 messages;
• Transform messages from one HL7 format to another to allow applications to communicate with one another.

Tasks that can be performed include:

• Conditional mapping (e.g. only map value if type is a String);
• Data modification (e.g. converting 'PATIENT' to 'Patient'); and
• Mapping multiple fields of a message to a single table column.

In the following sections, you will:

• Discover what Python scripts can be written in Chameleon, and the order in which they are executed;
• Learn about Chameleon-specific variables that have been defined for use in Python scripts.

	If you are new to Python or need more information on any of its features, see Learning Python. For a brief overview of Python and how it is used in Chameleon, refer to the Python Quick Reference Guide. This guide is in PDF format; to view it, you must have Adobe Reader installed on your computer.

	Iguana Users If you are using Iguana, knowing Python will be useful for you too. In Iguana, all message manipulation functionality is accomplished using a Message Definition File (VMD) and a pair of channel components. This VMD file is created and edited using Chameleon, and can contain Python scripts to manipulate incoming or outgoing HL7 messages. For a step-by-step tutorial that shows how to use Python in Iguana, see HL7 Transformation.