It’s simple enough, we just need to open the file in append mode. Opening an existing zip file in write mode will erase the zip, so be careful when you’re using that mode. Let’s say theres a ...

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.