import re
p = re.compile(r'\bsid:\W*(?P<sid>\w+)')
#test_str = "sid:I118uailfriedx151201005423521\">>" # => I118uailfriedx151201005423521
test_str = "sid:<<\"I118uailfriedx151201005423521" #
m = p.search(test_str)
if m:
print(m.group("sid"))
aW1wb3J0IHJlCnAgPSByZS5jb21waWxlKHInXGJzaWQ6XFcqKD9QPHNpZD5cdyspJykKI3Rlc3Rfc3RyID0gInNpZDpJMTE4dWFpbGZyaWVkeDE1MTIwMTAwNTQyMzUyMVwiPj4iICMgPT4gSTExOHVhaWxmcmllZHgxNTEyMDEwMDU0MjM1MjEKdGVzdF9zdHIgPSAic2lkOjw8XCJJMTE4dWFpbGZyaWVkeDE1MTIwMTAwNTQyMzUyMSIgIwptID0gcC5zZWFyY2godGVzdF9zdHIpCmlmIG06CglwcmludChtLmdyb3VwKCJzaWQiKSk=