Do I need to reinstall OS X after accidentally removing Python? I managed to delete my python in usr/bin by foolishly doing sudo rm /usr/bin/python and now it seems like I need to reinstall my OS.

First off is this necessary? And secondly is there an easy way to do this without having to erase everything on my disk?

In other words ideally I would like my programs I have installed to remain there after reboot saving me the trouble of having to install everything again to date. Is this possible?
This question probably has all the answers for you. In short there is no easy way. Your options are: 


Recover the files from a (Time machin) Backup, if existent.
Reinstall OSX, e.g. from the Recovery mode pressing  Command+R at the startup screen
Copy the missing files from the Recovery partition (check if the partition is up to date first). E.g. by doing cp -a /bin /Volumes/&lt;your disk name&gt;