import re
p = re.compile(r'@([^\s:]+)')
test_str = "@galaxy5univ I like you\nRT @BestOfGalaxies: Let's sit under the stars ...\n@jonghyun__bot .........((thanks)\nRT @yosizo: thanks.ddddd <https://y...content-available-to-author-only...o.com>\nRT @LDH_3_yui: #fam, ccccc https://m...content-available-to-author-only...s.com"
print(p.findall(test_str))
p2 = re.compile(r'(?:http|ftp|https)://(?:[\w_-]+(?:(?:\.[\w_-]+)+))(?:[\w.,@?^=%&:/~+#-]*[\w@?^=%&/~+#-])?')
print(p2.findall(test_str))