Extract Lines/Rows of Data from CSV Based on ID Match -- 2

I need to extract complete lines of data from multiple CSV files and save the results as another CSV file. Must maintain a tree of sorted keys and then use find on them instead of traversing whole lists Here is What I have I have hundreds of of source CSV files all with the same formatting. And I have a list of ID's (which are domains such as; [login to view URL], [login to view URL], [login to view URL]) I want the program to 1) read the IDs/domains from a text file or CSV file and then 2) go to each of the source CSV files and match a row/line based on the ID/domain 3) and pull the information and save the data as a results.csv. Keep in mind that I need to be able to make the program scan across many CSV files within one step. (Meaning, if I have 1000 files, I do not want to run it 1000 times.) Attached are sample files. 1 - The list of domains I want data for. 2 - A small sample list of all domains. 3 - The results of the data based on the domains I wanted data for (file 1) being taken from file 2. NOTE: Please tell me how you will build this so that I know you have reviewed the requirements. There are many people who reply to projects before they look at the details. "I can make it much faster in technical terms log N which will give you a very good speed and you will be able to get results of days in few minutes. what i will do is maintain a tree of sorted keys and then use find on them instead of traversing whole lists this requires some work." "Sure there are more ways I can have sorted structure and it will improve speed to 100 times. Will take me 3 hours to develop that though." Per Email: 040914 Thank you.