Your Python scripts can access the top-level Python module that is included with Chameleon and Iguana. This module contains global variables such as field and environment.

This top-level module is named __main__ (two underscore characters, followed by main, followed by two more underscore characters). To import from this module, use the import and from statements that you would normally use to import from an external module:

from __main__ import environment

You should note that importing a variable from __main__ creates a new reference to the original. This means that assigning a value to the local variable does not change the value in __main__. To assign to the variable, you need to supply the module name:

from __main__ import myvariable

__main__.myvariable += 1   # This assigns to the variable in __main__
myvariable += 1            # This does not affect the variable in __main__

This also means that if a variable is imported from __main__ and is later changed by a Chameleon script, the change is not made to your copy of the variable. For this reason, it is best not to import a variable if you want its value in your script to be synchronized with its value in __main__.

	If typing __main__ is inconvenient, you can specify an equivalent name for it: import __main__ as main main.myvariable += 1 # This assigns to the variable in __main__

	For more information on the functions and variables that are defined in the Python module, see Chameleon Python API. For details on how to use your own global variables in modules, see Global Variables.