t = '19:16:30'
mt = re.match(r'^(0[0-9]|1[0-9]|2[0-3]|[0-9])\:(0[0-9]|1[0-9]|2[0-9]|3[0-9]|4[0-9]|5[0-9]|[0-9])\:(0[0-9]|1[0-9]|2[0-9]|3[0-9]|4[0-9]|5[0-9]|[0-9])$', t)
print mt.groups() ip = '255.105.25.55'
ipm = re.match(r'^([1-9]?\d|1\d\d|2[0-4]\d|25[0-5])\.([1-9]?\d|1\d\d|2[0-4]\d|25[0-5])\.([1-9]?\d|1\d\d|2[0-4]\d|25[0-5])\.([1-9]?\d|1\d\d|2[0-4]\d|25[0-5])$',ip)
print ipm