Я не совсем уверен, но я бы предположил, что, возможно, выражение, подобное:
title="(.+?)">\s*(.+?)\s*<
может быть точкой для начала.
Test
import re
regex = r"title=\"(.+?)\">\s*(.+?)\s*<"
test_str = "<a class=\"FPmhX notranslate nJAzx\" title=\"ceorackz_adpp\" href=\"/ceorackz_adpp/\">ceorackz_adpp</a>"
matches = re.finditer(regex, test_str, re.DOTALL)
for matchNum, match in enumerate(matches, start=1):
print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group()))
for groupNum in range(0, len(match.groups())):
groupNum = groupNum + 1
print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum)))