import re

line=r'document.getElementById("URL_LABEL").innerHTML="<a name=\"link\" href=\"http://"+url+"\" target=\"blank\">"+url+"</a>"'

re_strings=re.compile(r"""   "
                            (?:
                            \\.|
                            [^\\"]
                            )*
                            "
                            |
                            '
                            (?:
                                [^\\']|
                                \\.
                            )*
                            '
                            """,re.VERBOSE);


for s in re.finditer(re_strings,line):
            print(s.group(0))