Pedro Bellini walks through the process of creating a manual aim set up in Maya, using the Maya Python API. Using only math operations and the Maya Python API, Pedro creates a similar set up to the Maya default Aim Constraint. Using the same techniques that are revealed in the tutorial, you should easily be able to create your own DG Aim Node for Maya.
In this video I walk the process of making an object point it’s (aim) axis to another object and how to control the up axisPedro Bellini
More With Python in Maya
There have been plenty of posts here on Python in Maya, ranging from getting started to more advanced topics. Chris Zubrigg has a great series for Maya Python tips and tricks with the post New Python Tutorial Series for Maya, Python Tips and Tricks. He also had a beginner series that is great for getting started using Python in Maya with the post Beginning Python for Maya Series Offers Starting Point to Learn Scripting in Maya.
Marco Giordano shared some tips for working with pointers to with the Maya API, in the post Tips for Working With Pointers Using the Maya Python API. He also had a look at using the Python Libraries in various ways in Maya, with the post Revealing the Power of Python Dictionaries in Maya.
Zeth Willie offered a basic look at using Python “for” and “while” loops in scripting with the post Understanding The basics of “For” and “While” Loops in Python for Maya. Zeth also offers a look at the basics for scripting ith Python in Maya with the post A Basic Overview for Using Python Scripts in Maya.
And finally, if you are looking for more information on how to load and use python scripts in Maya, Sam Wirch has a look at how to do that with the post How to Import and Run External Python Scripts in Maya.