This post explains how to write to a file in Python. You'll discover how to create word files (.docx), spreadsheets (.csv), text files, and more!

The problem I've noticed is that if I append the file with each of the 100k runs (one at a time), it can happen that two threads try to save to the file at the same time and some row (s) end up empty.

How to convert an XLS file to CSV Let’s say you have the file clients.xlsx and you need it converted to clients.csv to be then uploaded as a client list in your new CRM tool.