# coding: utf-8
txt = """uvr-10 340 00:1b:fc:20:de:29 11 20100101.uvr-10
uvr-10 340 00:1b:fc:20:de:29 11 20100102.uvr-10
uvr-10 340 00:1b:fc:20:de:28 11 20100106.uvr-10
uvr-10 340 00:1b:fc:20:de:29 11 20100109.uvr-10"""
z = dict(map(lambda x:[x.split(' ')[2],x],txt.split('\n')))
print '\n'.join(z[x] for x in z )
uvr-10 340 00:1b:fc:20:de:28 11 20100106.uvr-10
uvr-10 340 00:1b:fc:20:de:29 11 20100109.uvr-10