Adding in TPX Command

I have noticed that this command has gone un-implemented for a long time now, and i wanted to implement it myself, because it is a command i would use a lot. I hope that my coding style is okay, and that my code is sufficiently well-written enough to merge into. First PR, so I have no prior reference from which to see this. 

I am also sorry if this introduces any bugs. I tested it and did not find any, but a human is not omniscient. 
Thank you for your time and consideration.