PyDev not appearing in Eclipse after install
Had this same problem a few days ago.  You might have downloaded the wrong version of PyDev for your python version (2.7.5 or something is my python version, but I downloaded PyDev for version 3.x.x)
1) Uninstall your current version PyDev
2) you have to install the correct version by using the "Install New Software", then uncheck the "Show only newest software" or whatever it is.  Then select the version that matched your python version, and install :)
I have Java version 7 and had installed PyDev version 3.9 from Eclipse Marketplace..but it's not showing up in New project or in Windows perspective in Eclipse..Can some one please tell me what i need to do ???