from itertools import count
import re
keywords = ['Total item value', 'Total weight', 'Total volume']
lines = ['Total item value RSX 05,018.88\n',
'Total weight 90,969 EUR\n',
'Total volume -97.93 X3 Sca.\n',
'197.939 X3 Sca.']
pat = r'(?m)^(?:{0}).*(?:[\r\n]+(?!(?:{0})).*)*'.format("|".join([re.escape(x) for x in keywords]))
print(re.findall(pat, "\n".join(lines)))
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