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.

Writing to files is one ... In short, each line represents a row in a database and contains a series of values separated by commas. Each comma represents the start of a new column or cell!

Most hacker types don’t mind a command line interface ... have the option of creating a JSON file that Gooey can read if you don’t want to write Python. The utility of this is easy to see ...