Virtualenvwrapper.sh functions not available in bash shell

I'm doing a new install of virtualenvwrapper, and for some reason after running virtualenvwrapper.sh it's functions aren't available.

$ virtualenvwrapper.sh
creating.....
$ workon
workon: command not found

I know that it's running, aside from the successful creation of all the VE files, I've wrapped some of the function definitions in echo "please get h开发者_如何学Goere" statements and they all get hit.

So: what?

Oh I see, the correct thing to do is:

$ source virtualenvwrapper.sh

it was on my PATH, and getting run in a subshell, I guess.