“dunder” is short for double underscore. In Python, files, function and variable names beginning (and ending) with two underscore are quite common. The ones you probably come across most often are the __init__ method and the __init__.py file.

The term “dunder” is used when referring to these names in a conversation. Saying “the underscore underscore init underscore underscore method” is very verbose, so instead, one might just say “dunder init” method.

If you use this term, observe the reaction of your conversational partner. If you get a blank stare (you could say they are dunderstruck), kindly explain what dunder means.

Header photo by Dan Meyers