Compares two joints hierarchies in Maya and returns the differences between the two hierarchies as a keyed dictionary

CompareJointHierarchies.py

import pymel.core as pm
import re
from pprint import pprint

def compare_joint_hierarchies():
    report = {}
    top_group_a, top_group_b = pm.ls(sl=True)[:2]
    report['top_group_a'] = str(top_group_a.name())
    report['top_group_b'] = str(top_group_b.name())
    
    joints_a = joint_hierarchy_status(top_group_a)
    joints_b = joint_hierarchy_status(top_group_b)
    report['top_group_a_joints'] = 'Number of joints %d' % len([convert_to_shortname(joint) for joint in joints_a])
    report['top_group_b_joints'] = 'Number of joints %d' % len([convert_to_shortname(joint) for joint in joints_b])
    
    
    bigger, smaller = (max(joints_a, joints_b), min(joints_a, joints_b))
    report['smaller_top_group'] = report['top_group_a'] if smaller == joints_a else report['top_group_b']
    report['bigger_top_group'] = report['top_group_a'] if bigger == joints_a else report['top_group_b']
    difference_smaller = list()
    
    for joint_a in smaller:
        for joint_b in bigger:
            if convert_to_shortname(joint_a) in convert_to_shortname(joint_b):
                bigger.remove(joint_b)
                break
        else:
            difference_smaller.append(joint_a)
    
    report['zJoints missing from bigger'] = [convert_to_shortname(joint) for joint in bigger]
    report['zjoints missing from smaller'] = [convert_to_shortname(joint) for joint in difference_smaller]
    print ('\n\n---------------------------HIERARCHY REPORT BELOW---------------------------\n\n')
    return report
    
def joint_hierarchy_status(top_group):
    joints = top_group.listRelatives(ad=True, type='joint')
    if isinstance(top_group, pm.nt.Joint):
        joints.append(top_group)
    joints.sort(key=natural_keys)
    return joints

def natural_keys(text):
    '''
    alist.sort(key=natural_keys) sorts in human order
    http://nedbatchelder.com/blog/200712/human_sorting.html
    (See Toothy's implementation in the comments)
    '''
    return [ int(c) for c in [f for f in re.split('(\d+)', text.name()) if f.isdigit()] ]
    
def convert_to_shortname(node):
    return str(node.split(':')[-1].split('|')[-1])
        
pprint(compare_joint_hierarchies())