Hi, I have a text file input and I want to parse line by line and map each line to another format. But at the same time, I want to filter out some lines I do not need.
I wonder if there is a way to filter out those lines in the map function. Do I have to do two steps filter and map? In that way, I have to scan and parse the lines twice in order to filter and map. If I map those unwanted line to null and filter out null, will that work? never tried yet. Thanks, Zheng zheng