ankibackup
I am using Anki both on my desktop and mobile.
I created a long deck on desktop by hand and ran sync. It asked me whether I want to download or upload, and I selected to download. I didn't think it would delete the existing deck just because it is absent on server, but it did just that.
Is it possible to restore it?
The desktop Anki version will allow you to import "Text separated by tabs or semicolons." Use this option to choose your CSV file. After opening the file, you will be presented with a dialog which allows you to customize how your data is imported. One of the settings is an option that lets you choose the delimiter. Change this to a comma, and it should work for you.
Well, this question didn't take long to find an answer to. There's an add-on at AnkiWeb.net that enables exporting to .csv. Job done.
Best Answer
The other answer is about Linux system, but in macOS, the backup directory is located in the following path: