替换列表列表中的某些元素

Question

如果我可能在python中有列表列表，如何替换某些元素？我只想改变个别元素

def replace_item(the_list,toBeReplaced,toBeReplacedBy):
    for each_item in the_list:
        if isinstance(each_item,list):
            replace_item(each_item,toBeReplaced,toBeReplacedBy)
        else:
           if each_item == toBeReplaced:
                each_item=toBeReplacedBy

    return the_list

如果我有一个列表

[[2,3],[[2,3,5,6],2,6,3],[1,2]] 

如果我想用零替换2，那么结果应该是

[[0,3],[[0,3,5,6],0,6,3],0,6,3,[1,0]]

Answer 1

通过将toBeplacedBy分配给each_item，您不会更改the_list中的项目。这就是你如何做到的。

def replace_item(the_list,toBeReplaced,toBeReplacedBy):
        for index,each_item in enumerate(the_list):
            if isinstance(each_item,list):
                replace_item(each_item,toBeReplaced,toBeReplacedBy)
            else:
                if each_item == toBeReplaced:
                    the_list[index]=toBeReplacedBy

        return the_list