about my answer to stackoverflow "pip: dealing with multiple Python versions?" question

shell-output

$ pip install --upgrade pip
Downloading/unpacking pip
  Downloading pip-1.2.1.tar.gz (102Kb): 102Kb downloaded
  Running setup.py egg_info for package pip
    
    warning: no files found matching '*.html' under directory 'docs'
    warning: no previously-included files matching '*.txt' found under directory 'docs/_build'
    no previously-included directories found matching 'docs/_build/_sources'
Installing collected packages: pip
  Found existing installation: pip 1.0.2
    Uninstalling pip:
      Successfully uninstalled pip
  Running setup.py install for pip
    
    warning: no files found matching '*.html' under directory 'docs'
    warning: no previously-included files matching '*.txt' found under directory 'docs/_build'
    no previously-included directories found matching 'docs/_build/_sources'
    Installing pip script to /Users/hugo/.virtualenvs/stackoverflow/bin
    Installing pip-2.7 script to /Users/hugo/.virtualenvs/stackoverflow/bin
Successfully installed pip
Cleaning up...
$ pip --version
pip 1.2.1 from /Users/hugo/.virtualenvs/stackoverflow/lib/python2.7/site-packages (python 2.7)
$ pip-2. # TAB TAB
pip-2.4  pip-2.7  
$ which pip-2.7 
/Users/hugo/.virtualenvs/stackoverflow/bin/pip-2.7
$ which pip
/Users/hugo/.virtualenvs/stackoverflow/bin/pip
$ which pip-2.4
/Library/Frameworks/Python.framework/Versions/Current/bin/pip-2.4