import re
 
s='''RECORD1  Sed similique nostrum quibusdam minus. Rerum repudiandae et ipsum numquam commodi repellendus. Aut minima ratione vel 
beatae minima reprehenderit provident neque. Earum quam temporibus repudiandae quidem officiis
RECORD2 Sed similique nostrum quibusdam minus. Rerum repudiandae et ipsum numquam commodi repellendus. Aut minima ratione vel 
beatae minima reprehenderit provident neque. Earum quam temporibus repudiandae quidem officiis
RECORD3   It is a long established fact that a reader will be distracted by the readable content of a page when looking at its 
layout. 
RECORD4 '''
regex = r"(?s)(RECORD.*?\s).*?(?=(RECORD.*?\s))"
matches = re.finditer(regex, s)
for matchNum, match in enumerate(matches):
	matchNum = matchNum + 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)))

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