stretchy IK Handle - Rough

gistfile1.txt

def buildIK() :
    
    obj = 'Leg' 
    side = 'LF'
    list = ['jntLeg01LF','jntLeg02LF','jntLeg03LF']
    
    srtJoint = list[0]
    midJoint = list[1]
    endJoint = list[2]
    parent = ''
    
    handle = cmds.ikHandle(n=obj + '_IKHandle_' + side, sj = srtJoint, ee = endJoint)[0]
    eff = cmds.rename('effector1' , obj + '_effector' + side)

    Len = cmds.createNode('curveInfo', n= obj + side + 'Len')
    
    
    srtPos = cmds.xform(srtJoint,q=1,t=1,ws=1)
    endPos = cmds.xform(endJoint,q=1,t=1,ws=1)

    cmds.distanceDimension(sp=srtPos,ep=endPos)
    
    srtLoc = cmds.rename('locator1', obj + '_Start_DistLoc_' + side)
    endLoc = cmds.rename('locator2',obj + '_End_DistLoc_' + side)
    dist = cmds.rename('distanceDimension1','distance_' + obj + side)
    
    if parent == '' :
        parent = controls.ring(nameSpace + obj + 'IK' + side, size = 1)
        utils.snapPoint(endJoint, parent)
    cmds.parent(endLoc,parent)
    cmds.parent(srtLoc,srtJoint)
    cmds.parent(obj + '_IKHandle_' + side,parent)


    #measure bone length
    driver = 'distance_' + obj + side + 'Shape.distance'
    srtLen = cmds.getAttr(midJoint + '.tx')
    endLen = cmds.getAttr(endJoint + '.tx')
    limbLen = srtLen + endLen
    

    cmds.setDrivenKeyframe (midJoint,cd=driver,dv=limbLen,attribute='translateX',v=srtLen) 
    cmds.setDrivenKeyframe (midJoint,cd=driver,dv=(limbLen*2),attribute='translateX',v=(srtLen*2)) 
    ##

    cmds.setDrivenKeyframe (endJoint,cd=driver,dv=limbLen,attribute='translateX',v=endLen) 
    cmds.setDrivenKeyframe (endJoint,cd=driver,dv=(limbLen*2),attribute='translateX',v=(endLen*2)) 
        
    
    ##
    mel.eval('selectKey -add -k -f 8.022469 -f 16.044937 ' + midJoint + '_translateX ;')
    mel.eval('setInfinity -poi cycleRelative;') 
    mel.eval('selectKey -add -k -f 8.022469 -f 16.044937 ' + endJoint + '_translateX ;')
    mel.eval('setInfinity -poi cycleRelative;') 

    #hide extra junk
    cmds.setAttr (srtLoc + '.visibility', 0)
    cmds.setAttr (endLoc + '.visibility', 0)
    cmds.setAttr (dist + '.visibility', 0)
    cmds.setAttr (handle + '.visibility', 0)
    
    grp = cmds.group(dist, n = nameSpace + 'grp' + obj + 'Distance')

    if objExists(nameSpace + 'grpEX') == True :
        cmds.parent(grp, nameSpace + 'grpEX')