Python in Maya

Autodesk Maya supports the use of Python-style scripting wherever you used to use MEL commands. The implementation of Python scripting in Maya provides the same access to native Maya commands as is provided through MEL. That is, all of the built-in Maya commands, such as sphere, ls, and so on, are accessible through Python.

Commands that are written as MEL scripts—which are actually MEL global procedures (procs)—are accessible using a call to access MEL (maya.mel.eval). For more information, see MEL/Python communication.

NoteThere are certain MEL built-ins that are not available in Python, though they generally have Python counterparts.These include math functions (abs, sin, cos, ...) and string functions (match, gmatch, tokenize...). (The set of MEL built-in functions can be considered the MEL runtime library.)

Python comes with a wide variety of standard modules that provide similar functionality. Refer to Python documentation for information on what is available and how to use these functions in your Python scripts.

Python Command Reference

There is a Python command reference similar to the MEL command reference. For details on all Python commands, refer to the Python command reference documentation in Maya Help.

You can access the help by selecting Help > Python Command Referenceor open the Maya Help ( Help > Maya Help), and when the Help appears, click CommandsPython at the bottom of the navigation frame.

Version

Maya installs Python with your Maya installation. Maya uses Python version 2.5.1 on all supported platforms. The standalone Python shell for Maya is named mayapy.exe on Windows and mayapy on Linux and Mac OS X.

External resources

For information about getting started with Python, including reference material and resources, see:

www.python.org

Initializing the Maya Environment in and for Python

Maya runs any Python commands in the userSetup.py file whenever it starts up. You can use this file to set up your working environment or execute commonly used Python commands such as importing the maya.cmds module.

The userSetup.py script is executed during the initialization and setup phase of Maya; therefore, only commands which set up your working environment and have no dependencies on Maya functionality can be successfully run in this script.

NoteYou can use maya.utils.executeDeferred() to delay code execution until after the Maya scene is initialized. For more information, see maya.utils.

Create a file named userSetup.py in the following folder:
- Windows: <drive>:\Documents and Settings\<username>\My Documents\maya\<Version>\scripts
- Mac OS X: ~/Library/Preferences/Autodesk/maya/<version>/scripts
- Linux: ~/maya/<version>/scripts
In the userSetup.py file, type the commands you want Maya to run on start up; for example, import maya.cmds as mc.
NoteMake sure you save the file with the right extension (.py).

Adding items to your Python path

To add items to your path in Python, do one of the following:

Set PYTHONPATH in your Maya.env file, or in your environment before you run Maya
Append to sys.path in your userSetup.py or other script once Maya is running.

Here is an example of appending sys.path

import sys sys.path.append( '/Users/jdoe/maya/Scripts' )

MEL and Python importing

If you have a MEL script in your path, you do not need to source it before accessing any single global procedure it contains with the same name. However, Python requires you to import a script explicitly before accessing any classes or functions it contains; for example:

# This will access the function "bar" in the file "foo.py"

import foo

foo.bar()