import re
string='Path Group: sclk ;djlasfhv slack 5t45545 545 (VIOLATED) -0.8568 Path Group: sclk ;djlasfhv slack (VIOLATED) -0.88 Path Group: sclkasfhv slack (VIOLATED) -0.121'
violation = re.findall(r'Path Group: sclk[^V]*(?:V(?!IOLATED\))[^V]*)*VIOLATED\)\s*(-[0-9]\.[0-9]+)', string)
print violation
aW1wb3J0IHJlCgpzdHJpbmc9J1BhdGggR3JvdXA6IHNjbGsgO2RqbGFzZmh2IHNsYWNrIDV0NDU1NDUgNTQ1IChWSU9MQVRFRCkgICAgLTAuODU2OCAgICAgIFBhdGggR3JvdXA6IHNjbGsgO2RqbGFzZmh2IHNsYWNrIChWSU9MQVRFRCkgICAgICAgLTAuODggUGF0aCBHcm91cDogc2Nsa2FzZmh2IHNsYWNrIChWSU9MQVRFRCkgICAgICAgICAgICAgICAgLTAuMTIxJwp2aW9sYXRpb24gPSByZS5maW5kYWxsKHInUGF0aCBHcm91cDogc2Nsa1teVl0qKD86Vig/IUlPTEFURURcKSlbXlZdKikqVklPTEFURURcKVxzKigtWzAtOV1cLlswLTldKyknLCBzdHJpbmcpCnByaW50IHZpb2xhdGlvbg==