get_mat_assigned_for_obj.py

import pymel.core as pm

def get_mat_assigned_for_obj(mat, obj):
    if issubclass(type(mat), (str, unicode)):
        mat = pm.PyNode(mat)
    if issubclass(type(obj), (str, unicode)):
        obj = pm.PyNode(obj)
        
    members = mat.connections(type=pm.nt.ShadingEngine)[0].members()
    
    obj_typ = type(obj)
    if issubclass(obj_typ, pm.nt.Transform):
        shp = obj.getShape()
    elif issubclass(obj_typ, pm.nt.Mesh):
        shp = obj
    else:
        raise ValueError("Invalid object! needs to be a Transform or Mesh")
    
    mat_ass_objs = []
    
    for m in members:
        m_type = type(m)
        if issubclass(m_type, pm.Component):
            if m.node() == shp:
                mat_ass_objs.append(m)
        elif issubclass(m_type, pm.nt.Mesh):
            if m == shp:
                mat_ass_objs.append(m)
                
    return mat_ass_objs
    
if __name__ == "__main__":
    pm.select(get_mat_assigned_for_obj(u"TEST", u"pTorus1"), replace=True)