How to export product data from we-retail into csv

You would need to write a custom Service that reads the JCR data you want to export, format the data to CSV and then return it. Purhaps a Sling Servlet.

My first answer is based on if you want to perform additional operations on the data. For example, you can use Java logic to perform some additional encoding operations and check the data and so on.

Alternatively - you can simply dump data by following this: Export to CSV