user_agents = [
    'User-Agent,Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0',
    'User-Agent,Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_8; en-us) AppleWebKit/534.50 (KHTML, like Gecko) '
    'Version/5.1 Safari/534.50',
    'User-Agent,Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)',
    'User-Agent, Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv,2.0.1) Gecko/20100101 Firefox/4.0.1',
    'User-Agent,Mozilla/5.0 (Windows NT 6.1; rv,2.0.1) Gecko/20100101 Firefox/4.0.1'
]
