How do I import nltk in python?

[RSJinx]

Hi. I'm totally new to Python and only have a little experience with C++. So, to begin with, I don't really know what I'm doing. I installed nltk three times - each time it said the installation was successful. But trying to import nltk only results in an error message. I tried what I found on these pages: http://groups.google.com/group/nltk-users/browse_thread/thread/509dac376bf06300?fwc=1 and http://www.nltk.org/download. This is what happened:

Python 2.6.4 (r264:75821M, Oct 27 2009, 19:48:32) 
[GCC 4.0.1 (Apple Inc. build 5493)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
 
>>> import nltk
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named nltk
 
>>> cd /tmp/nltk-installer
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'cd' is not defined
 
>>> sudo python setup.py install
  File "<stdin>", line 1
    sudo python setup.py install
              ^
SyntaxError: invalid syntax
 
>>> sudo easy_install -U py
  File "<stdin>", line 1
    sudo easy_install -U py
                    ^
SyntaxError: invalid syntax
>>> 
 

Any ideas? I'm sure it's something really simple. ^_^

Thanks!

[bvdet]

If you have more than one version of Python installed, you may have installed nltk to a different version of Python than the version currently active.

[RSJinx]

Thank you! I figured it out. Like I said, totally new to this, and I didn't realize that I needed to just be in the terminal, not python, to make those troubleshooting commands work. It all works now. : )