The following basic building blocks can be found in most scripts written in Python:

• The data, or values, that the script works with;
• Variables that store and manipulate these values;
• Comments that explain what your script does;
• Arithmetic operations that update the values stored in variables.

In addition, most standalone Python scripts contain print statements that display values or the contents of variables on the screen. A Python script contained in Chameleon may contain print statements if you are debugging the script or logging information.

Here is an example of a simple Python script that uses these basic building blocks:

# Convert a patient's temperature from Celsius to Fahrenheit

temperature = 37.0
result = temperature * 1.8 + 32
units = "Fahrenheit"
print "The converted temperature is", result, "degrees", units

This script consists of a sequence of instructions, or statements, to be performed. You can use a Python interpreter, such as IDLE, to perform these instructions.

When an interpreter performs the instructions in the script, the following output is displayed:

The converted temperature is 98.6 degrees Fahrenheit

	Some useful terminology: A Python script is also sometimes called a Python program; the two terms are used interchangeably. When an interpreter is asked to perform the instructions in a script, this is sometimes referred to as running the script or executing the script.

If you have previous programming experience, you will have little difficulty understanding the code in this example, as Python is similar to many programming languages in common use.

	The IDLE interpreter is automatically included with every standalone version of Python. For details on how to use IDLE, see the Using IDLE section of the online Python documentation. If you do not have a standalone version of Python on your computer, you can download the latest version from the Python web site. Or, if you prefer, you can download a standalone implementation of the version of Python that is currently used in Chameleon. This provides another way to test your Chameleon Python scripts on your computer.

If you do not have programming experience, the following sections describe the features of Python that are illustrated in this example, along with some other basic features: