Example of an approach to generating a unique name for a Maya object, using Maya commands API

maya_unique_name.py

"""
Re: https://groups.google.com/d/topic/python_inside_maya/ndjexeQrZs8/discussion

Example of an approach to generating a unique name for a Maya object.

Author: Justin Israel (justinisrael@gmail.com)
"""

def uniqueNamePattern(base="object", padding=1):
    """
    Find the next available Maya object name, starting
    with the given base name. Subsequent names will have
    a number appended to the end.

    A custom position for the number counter can be specified
    by using a python format string pattern, like:
        "prefix_{0}_suffix"

    In this case, the {0} will be replaced with the counter:
        "prefix_2_suffix"
    
    If padding is > 1, pad the counter to the given width, 
    with zeros
    """
    i = 1
    # Have we been given a string with a format placeholder ({0})?
    customRepl = base.format('x') != base  

    if customRepl:
        # Apply custom padding if needed
        iStr = str(i) 
        if padding > 1:
            iStr = iStr.zfill(padding)
            
        # Start with our first counter value
        name = base.format(iStr) 
        
    else:
        # Start with the original base value
        name = base 
 
    
    # Keep looping while the name exists in Maya
    while cmds.objExists(name):
        i += 1
        
        # Apply custom padding if needed
        iStr = str(i) 
        if padding > 1:
            iStr = iStr.zfill(padding)
            
        # Update name with new version, formatted with 
        # updated counter value
        if customRepl:
            name = base.format(iStr) 
        else:
            name = "{0}{1}".format(base, iStr) 

    return name 

# Example usage
cmds.group(name=uniqueNamePattern("test_{0}_GRP"), 3)