search address and response address is different

[dnickerson]

I used pywallet (version: pywallet.py 1.1) web interface to get info for this address from a bitcoin core wallet: 1mRPTqz1dhDbTkz5p63LPCv4XaGofVWhn

Pywallet responded with this:
Address (Bitcoin): 12nYPfaVHAMfuxMSyx6sBnzNFMHFymFR8o
Privkey (Bitcoin): 5H...
Hexprivkey:
Hash160:
Pubkey: 0484794930fa32ea6fd53c89aa2244f15916c1f248db7a02007f9f53c496dea3d69d5b0445f60678a3dbae27f01078e4a60b40a7c05c466b4034609236ace4950d

Why is the key different? My objective is to get the private key for the above public key.