我正在尝试实现一个lstm模型，在该模型中我需要对列进行填充。这该怎么做？

Question

让我有一个列表-

               task= [ 
                     [  [1,2,3], [2,3,5] ]
                     [  [1,2,3], [2,3,5] , [4,5,6] ]  
                     ]

我想像这样-

                task= [ 
                      [  [0,0,0], [1,2,3], [2,3,5]  ]
                      [  [1,2,3], [2,3,5] , [4,5,6] ]  
                      ]