While most animation in Maya is created manually, it can often be useful to drive attributes directly via script, especially for mechanical objects or background items. One way to approach this is through Maya's expression editor.

In addition to creating expressions via the expression editor, it is also possible to create expressions with scripting, in a beautiful example of code-driven code. In this example, we'll be creating a script that can be used to create a sine wave-based expression to smoothly alter a given attribute between two values. Note that expressions cannot actually use Python code directly; they require the code to be written in the MEL syntax. But this doesn't mean that we can't use Python to create expressions, which is what we'll do in this example.