In bash, "which" gives an incorrect path - Python versions

Can anyone explain how python 2.6 could be getting run by default on my machine? It looks like python points to 2.7, so it seems like 开发者_Go百科which isn't giving me correct information.

~> python --version
Python 2.6.5
~> which python
/opt/local/bin/python
~> /opt/local/bin/python --version
Python 2.7.2
~> ls -l /opt/local/bin/python
lrwxr-xr-x  1 root  admin  24 12 Oct 16:02 /opt/local/bin/python -> /opt/local/bin/python2.7

When I generate an error, I see what's really getting run. Why could this be?

~> python -error-making-argument
Unknown option: -e
usage:     /Library/Frameworks/Python.framework/Versions/2.6/Resources/Python.app/Contents/MacOS/Python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Try `python -h' for more information.

And how can I correct it?

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From suggestions in comments:

~> alias
alias cp='cp -i'
alias gcc='gcc -Wall'
~> type python
python is /opt/local/bin/python

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Bash uses an internal hash table to optimize $PATH lookups. When you install a new program with the same name as an existing program (python in this case) earlier in your $PATH, Bash doesn't know about it and continues to use the old one. The which executable does a full $PATH search and prints out the intended result.

To fix this, run the command hash -d python. This will delete python from Bash's hash table and force it to do a full $PATH search the next time you invoke it. Alternatively, you can also run hash -r to clear out the hash table entirely.

The type builtin will tell you how a given command will be interpreted. If it says that a command is hashed, that means that Bash is going to skip the $PATH search for the executable.

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I just checked my .bash_profile, and it contained the following:

# Setting PATH for MacPython 2.6
# The orginal version is saved in .bash_profile.pysave
PATH="/Library/Frameworks/Python.framework/Versions/2.6/bin:/usr/local/git/bin:${PATH}"
export PATH

Commenting this out has fixed my problem.

If someone can tell me why which and type still gave incorrect answers, I'd be very grateful, and will give them a check-mark!

Thanks for all your guidance!