From the command line (Mac OS), when I execute 'echo $PYTHONPATH' I get:
> /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7 If I then enter the Python interpreter and do the following:
>>> import os >>> os.environ['PYTHONPATH'] Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/UserDict.py", line 23, in __getitem__ raise KeyError(key) KeyError: 'PYTHONPATH' Why would this happen?