When Autodesk added support for Python into Maya 8.5, few people understood the implications. It was a decision that has fundamentally changed the way 3D art gets done. Now, years later, we stand on the edge of realizing its promise.
The promise of Python in Maya goes beyond just a familiar language with a great syntax. Any language could have been chosen to bind to Maya; and most would have been more familiar, and with a better syntax than MEL, and easier to use than C++. So, why Python?
The promise goes beyond a powerful language with lots of built-in features. Python is said to have batteries included, but so do other languages, and Autodesk certainly has lots of batteries in Maya that now also exist in Python. So, again, why Python?
The promise goes beyond having a single language for scripting, API use, and plugins. It goes beyond the endless third-party libraries maintained by a large community. It goes beyond having powerful development tools.
The promise of Python in Maya is all of these things and more. You can learn how to use the language by leveraging a wide variety of resources that have nothing to do with Maya. You can easily translate what you know of MEL and the C++ API and use it in Python, but with an improved development velocity and maintainability of code. You can use your favorite standard Python editor and tools. You can learn about the language from a technical and design perspective and apply that to improve your programming in Maya. You can be part of a large, vibrant, diverse community of developers on the forefront of multiple areas of technology.
Join me as we explore topics that will allow you to unleash the power of Maya through Python. Together, we'll learn how Python works both under the hood and over it, how Maya integrates with Python, and how the elegant PyMEL builds on that integration. We will drill down into what makes Python code beautiful and idiomatic, and how we can use these concepts and Python's language features to make our Maya Python code expressive and elegant. We will leverage third-party solutions for networking and user interfaces, to compliment and extend what is included with Maya and Python. We will decouple Python code from Maya dependencies, making our work go smoother and faster
This book is not a reference. It is not a cookbook, and it is not a comprehensive guide to Maya's Python API. It is a book that will teach you how to write better Python code for use inside of Maya. It will unearth interesting ways of using Maya and Python to create amazing things that wouldn't be possible otherwise. While there is plenty of code in this book that I encourage you to copy and adapt, this book is not about providing recipes. It is a book to teach skills and enable.
This is a book which, I hope, helps realize the promise of Python in Maya.
Chapter 1, Introspecting Maya, Python, and PyMEL, explores how Maya and Python work individually and together to create a powerful programming and scripting environment. It covers some of the key technical underpinnings for the rest of the book.
Chapter 2, Writing Composable Code, introduces the practice of writing code that can be reused in many places. Composable code is a fundamental concept for the rest of the skills taught in this book.
Chapter 3, Dealing with Errors, teaches you all about exceptions and errors in Maya and Python. We explore several strategies for handling them effectively.
Chapter 4, Leveraging Context Managers and Decorators in Maya, covers context managers and decorators, which are two powerful features of Python, and how they can be used to simplify your code.
Chapter 5, Building Graphical User Interfaces for Maya, demonstrates the PySide and PyQt frameworks, how to abstract your user interface code from underlying logic, and a strategy of building GUIs to maximize maintainability and productivity.
Chapter 6, Automating Maya from the Outside, shows how Maya can be controlled from another process, explains how request-reply systems work, and builds a fully featured automation system on these principles.
Chapter 7, Taming the Maya API, introduces the Maya Python API and how types and classes work in Python and Maya. It contains a number of examples to demonstrate the API, as well as a Maya command plugin.
Chapter 8, Unleashing the Maya API through Python, covers the creation of a library to easily create Maya plugin nodes, demonstrating how to map the Maya API onto Pythonic idioms using metaprogramming.
Chapter 9, Becoming a Part of the Python Community, goes over the concepts behind open source software, demonstrates how to find and use third-party modules, explains how to create your own open source project, and tours the Python and Maya programming communities.
Appendix, Python Best Practices, explains in detail various Python language features and miscellaneous, but very relevant, topics.
You will need a copy of Autodesk Maya 2013 for this book. Newer versions are fine, and older versions that use Python 2.6 (2011, 2012) should be acceptable as well. Any operating system capable of running Maya (Windows, OS X, Linux) should work, though you will need to translate things such as file paths to what is appropriate on your system.
I would also suggest having an install of Python 2.6 or 2.7 outside Maya for exploring and running some of the samples that can be run from the interactive interpreter prompt. You can download Python 2.6 or 2.7 from http://www.python.org/download, or it may be installed on your Mac or Linux OS already!
Finally, I strongly suggest installing both a powerful text editor and an Integrated Development Environment (IDE). Python is a real programming language, and you should use the powerful tools available. If you are an experienced Python user already happy with vim, I don't expect to convert you. But if you are a converted MEL scripter playing around in Notepad, it is time to embrace your good fortune!
For a text editor, Sublime Text (http://www.sublimetext.com) is popular, cross-platform, and free to use on an unlimited trial. Notepad++ (http://notepad-plus-plus.org) is excellent if you are on Windows and prefer free and open source. There are dozens of other good text editors, and if the two editors mentioned here do not tickle your fancy, you should keep trying until you find one that does.
Finally, the choice of IDE is usually a contentious topic. For Python, however, I can confidently say PyCharm (http://www.jetbrains.com/pycharm/) by JetBrains is the premiere IDE, and my personal favorite. It has a free and quite powerful Community Edition as well. Other popular options are Wing IDE (http://www.wingware.com) and Eclipse with PyDev (http://pydev.org). Experiment with a few different programs, but whatever you do, move past IDLE, the IDE bundled with Python!
Do you currently use Python with Maya and ask yourself: "Can I do better?"
Are you a MEL scripter who has started using Python and want to know what all the fuss is about?
Are you a Python programmer who is starting with Maya and believes there must be a better way?
Have you been using Python in Maya for a while but work hard to continuously improve?
Some basic experience with Python and Maya is expected. This book does not cover those most primitive topics that are inevitably learned through introductory Maya and Python use.
Even more than experience, this book requires a willingness to learn. Some of the more advanced or unfamiliar topics may feel a bit like learning how to ride a bicycle, but keep peddling and you'll get the hang of things in no time.
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text are shown as follows: "We can include other modules through the use of the import statement."
A block of code is set as follows:
def spam():
return 'spam!'When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
def more_spam():
spams = ' '.join([spam()] * 5)
return spamsAny command line input or output is written as follows:
> mayapy --version Python 2.6.4
Code meant to be entered by the Python interactive interpreter uses its familiar conventions. Input lines are prefixed with ">>>". Continuations for multiline statements are prefixed with "...". Output from the interpreter has no prefix:
>>> 'This is input'.replace('in', 'out')
'This is output'
>>> if True:
... print 'Hello!'
HelloNew terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Clicking on the Next button moves you to the next screen".
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The code for this book is also available on GitHub, at https://github.com/rgalanakis/practicalmayapython. See the Appendix, Python Best Practices, for more information about the GitHub repository.
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