import re
str = ("< @@@@July 2nd 2018 Idustry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electroni@@@@@@c typesetting,> remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum > <@@@@August 1st 2019 dustry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting,> remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset she$$$$$$$ets containing Lorem Ipsum passages, and more rece#####ntly with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum <August 2nd 2019 cently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum > <@@@@August 1st 2019 dustry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scramble#######d it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting,> remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum >\n\n"
       "< @@@@July 2nd 2018 Idustry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting,> remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum >")
pattern = re.compile(r"<\s*@+.*?(?=<@|$)", re.MULTILINE)
print (pattern.findall(str))

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