index data item

If the item is an index, then you parse the object and create an object representing the data you are about to process: the keyword associated with the index and the number of tweets in the index.

如果条目是索引，那么您就解析该对象并创建一个表示您要处理的数据的对象：与索引相关联的关键词和索引中tweet的数量。

If the data is stored sequentially, the time to find the item is proportional to the size of the list. For each element, a hash function calculates a number, which is used as an index into the table.

如果数据是序列存储的，从中查询一个项的时间取决于数据列的大小。

We examine each row in turn, obtaining a model index for the first item in each row, and read the data stored for that item in the model.

我们按顺序逐行检查，获得每行第一个项的模型索引，然后读取存储在模型项里的数据。