If you have installed any python versions from source , then also you can face this problem.
Follow these instructions and things should work out:
Open a terminal Ctrl+Alt+T(Open Applications menu, Accessories, Terminal). Run
sudo nautilus (no quotes), giving your password when prompted.
Using the file browser that opens, navigate to
Delete the file called
Right-click the file called 'python' and click copy. Paste it into
Go back to '/usr/bin/' and copy 'python2.6' and paste it into
Do the same with the file called
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