fixupCyclicAnimLayers.py

import pymel.core as pmc

def fixupCyclicAnimLayers():
    """
    This function finds animation layer nodes which are connected to themselves, disconnects them, and HOPEFULLY finds
    the remaining unconnected animation curve, and plugs it back into the appropriate attribute.

    :return: None
    """
    
    # Get all our initial layer/curve data
    animLayers = [layer for layer in pmc.ls(type=['animLayer']) if 'BaseAnimation' not in layer.name()]
    animBlendNodes = pmc.ls(type=['animBlendNodeBase'])
    animCurveNodes = pmc.ls(type=['animCurve'])

    # Want to work on one layer at a time
    for animLayer in animLayers:
        for animBlend in [blendNode for blendNode in animBlendNodes if animLayer.name() in blendNode.name()]:
            blendNodeShortName = animBlend.shortName().split(':')[-1].split('_{layerName}'.format(layerName=animLayer.name()))[0]
            matchingCurves = [animCurve for animCurve in animCurveNodes if blendNodeShortName in animCurve.shortName()]

            # Find layer nodes that are connected to layer nodes, which... shouldn't be happening.
            connectedNodeAttrs = pmc.listConnections(animBlend, type='animBlendNodeBase',
                                                     plugs=True, d=True, s=False, c=True)

            animBlendAttrs = []

            for nodeAttr in connectedNodeAttrs:
                # GTFO cyclic connections!
                pmc.disconnectAttr(nodeAttr[0], nodeAttr[1])

                # Need to track what we're connecting back to
                animBlendAttrs.append(nodeAttr[1])

            i = 0
            for animCurve in matchingCurves:
                connectedAttrs = pmc.listConnections(animCurve)

                if len(connectedAttrs) == 0 or connectedAttrs is None:
                    try:
                        pmc.connectAttr(animCurve.output, animBlendAttrs[i])
                    except:
                        pass

                    i += 1