I was working on a CRM deployment and needed to migrate data from the old system to the new one.

The 50k rows of dataset had fewer than a dozen columns and was straightforward by all means. File size was smaller than 10MB. Sadly, that was enough to choke Excel on a modern day ThinkPad with 20GB RAM.

Whipping up some Pandas script was simpler. This was a quick summary. The Jupyter (iPython) version is also available.

https://gist.github.com/klopmp/6e1b5e4eec1b7f1ac6de1ba727a79d4c

The sample data files are published on Github: