I'm using emacs23 with tramp to modify python scripts on a remote host.
I found that when I start the python shell within emacs it starts up 
python on the remote host. 
My problem is that when I then try to call python-send-buffer via C-c C-c it comes up with the error

Traceback (most recent call last):
    File "", line 1, in ?
  ImportError: No module named emacs
Traceback (most recent call last):
    File "", line 1, in ?
  NameError: name 'emacs' is not defined

Now, I must admit that I don't really know what's going on here. Is there a way for me to configure emacs so that I can evaluate the buffer on the remote host?
Many thanks.
Edit: I've followed eichin's advice and re-implemented python-send-region. See my answer below.
Short answer: not without writing some missing elisp code.
Long version: In python.el, run-python adds data-directory (which on my Ubuntu 10.10 box is /usr/share/emacs/23.1/etc/ ) to $PYTHONPATH, specifically so that it can find emacs.py (as supplied by the local emacs distribution.)  Then it does a (python-send-string "import emacs") and expects it to work...
It looks like the defadvice wrappers that tramp uses don't actually pass PYTHONPATH, so this doesn't work even if you have the matching emacs version on the remote system.
If you M-x customize-variable RET tramp-remote-process-environment RET
then hit one of the INS buttons and add PYTHONPATH=/usr/share/emacs/23.1/etc then hit STATE and set it to "current session" (just to test it, or "save for future sessions" if it works for you) it almost works - the complaint goes away, in any case, because the remote python can now find the remote emacs.py.  If you now go back to the original question, doing python-send-buffer, you just run into a different error: No such file or directory: '/tmp/py24574XdA' because python-mode just stuffs the content into a temporary file and tells the python subprocess to load that.
You'd have to change python-send-region (the other functions call it) and particularly the way it uses make-temp-file to be tramp-aware - there's even a tramp-make-tramp-temp-file you could probably build upon.  (Be sure to post it if you do...)
evaluating buffer in emacs python-mode on remote host