import re
 
regex = r"(?:^\+\+(?=(?:(?!\-\-).)*\s+(calling[^\n]+)).*?\s+--)|(?:^\+\+(?=(?:(?!\-\-).)*\s+(?!calling[^\n]+)).*?\s+--)"
 
test_str = ("++ start line \n"
	"22 15:36:53 \n"
	"dog, cat, monkey, rat\n"
	"calling xxxxx\n"
	"animal already added\n"
	"-- exiting line\n\n\n"
	"++ start line \n"
	"12 12:56:34 \n"
	"cat, camel, cow, dog    \n"
	"animal already added\n"
	"-- exiting line\n\n"
	"++ start line \n"
	"12 12:56:34 \n"
	"cat, camel, cow, dog  \n"
	"calling pqr  \n"
	"animal already added\n"
	"-- exiting line\n\n")
 
matches = re.finditer(regex, test_str, re.DOTALL | re.MULTILINE)
 
for match in matches:
	print(match.group(1))
 
 

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