Get all UV shells from mesh object

getUvShells.py

import maya.OpenMaya as om
import maya.cmds as cmds

def getUvShelList(name):
    selList = om.MSelectionList()
    selList.add(name)
    selListIter = om.MItSelectionList(selList, om.MFn.kMesh)
    pathToShape = om.MDagPath()
    selListIter.getDagPath(pathToShape)
    meshNode = pathToShape.fullPathName()
    uvSets = cmds.polyUVSet(meshNode, query=True, allUVSets =True)
    allSets = []
    for uvset in uvSets:
        shapeFn = om.MFnMesh(pathToShape)
        shells = om.MScriptUtil()
        shells.createFromInt(0)
        # shellsPtr = shells.asUintPtr()
        nbUvShells = shells.asUintPtr()

        uArray = om.MFloatArray()   #array for U coords
        vArray = om.MFloatArray()   #array for V coords
        uvShellIds = om.MIntArray() #The container for the uv shell Ids

        shapeFn.getUVs(uArray, vArray)
        shapeFn.getUvShellsIds(uvShellIds, nbUvShells, uvset)

        # shellCount = shells.getUint(shellsPtr)
        shells = {}
        for i, n in enumerate(uvShellIds):
            if n in shells:
                shells[n].append([uArray[i],vArray[i]])
            else:
                shells[n] = [[uArray[i],vArray[i]]]
        allSets.append({uvset: shells})
    return allSets