text = """
Stuff before
This won't be matched...
Author(s)    : Firstname Lastname  
               Firstname Lastname  
               Firstname Lastname  
               Firstname Lastname
Other(s)     : Something else we won't match
               More shenanigans....
Only the author names will be matched.
"""
authors = re.search('Author\\(s\\)\\s*:\\s*(.*?)^[^\\s]', text, re.DOTALL |
    re.MULTILINE).group(1)
Converting Perl Regular Expressions to Python Regular Expressions