Forget a hashed executable location in bash interactive shell

Question

I often run into the case where I'm working inside a Python virtualenv, and I want to run an executable Python program (e.g., bpython). I run it, forgetting that I have not installed it in my virtualenv so it won't do the right thing. Then, I install bpython in my virtualenv, but if I try to run the new version, bash "remembers" the old one and calls it instead.

To be more concrete:

(venv)$ bpython
       (whoops, system-level bpython!)
(venv)$ which bpython
/usr/local/bin/bpython
(venv)$ type bpython
bpython is hashed (/usr/local/bin/bpython)
(venv)$ pip install bpython 
(venv)$ which bpython
/Users/lorin/.virtualenvs/venv/bin/bpython
(venv)$ type bpython
bpython is hashed (/usr/local/bin/bpython)

How do I tell the bash prompt to "forget" that the location of bpython is /usr/local/bin/bpython for that session?

Answer 1

You can tell bash to rehash:

hash -r

Answer 2

Resetting the PATH variable will do it:

export PATH=$PATH