[Video] Achieving R's `df1[B]= df2[B]` with Julia multiple-dispatch

It was asked on Twitter

“Hey #JuliaLang, is it possibly to sunset a DataFrame using a logical/Boolean matrix like you can in #rstats? Anything close would be helpful!”

So I made a video to show how to do this in Julia

and the Julia version is better.

This video is suitable for people learning Julia as well as it demonstrates some aspects of multiple-dispatch.