I am using emacs 23 -nw and xterm installed on Debian Squeeze. I need highlighting with python but I don't have it. How can I enable it? 
Edit:
Thanks for all answers, the problem is that

I have googled a lot, really.
I have the code on a file with extension .py
The script starts with #!/usr/bin/python, as one of the the answers points I have changed to !#/usr/bin/env python
I used M-x and tried to find something related to python, well there many options which do not solve my problem.

Sorry my question was not very precise and I even accept -10 but I don't have highlight which would give me red highlight for lines starting # etc. To be more precise I have a very a dull highlight; lines with # are white, lines between """ """ are green, some of the variable names are yellow but don't know why not all. [import, as, from] are light blue, [open, max, and other function names] are dark blue etc. And besides my 200 lines of code is working.
Emacs 23 should know about Python out of the box. Does the name of your Python file end with .py, or does the file have #!/usr/bin/env python as the first line? If you're creating a new file, make sure the filename ends with .py. You can also use M-x python-mode as mentioned in another answer. If none of that works, check that your terminal actually supports color.
Python highlighting in emacs