import re

x = 'envFlush({"user":"100002298034552","locale":"pl_PL","method":"GET","svn_rev":534081,"vip":"69.171.228.12","static_base":"http:\/\/static.ak.fbcdn.net\/","www_base":"http:\/\/www.facebook.com\/","rep_lag":2,"fb_dtsg":"AQBq8upG","ajaxpipe_token":"AXixBiqWh9DLwJtX","lhsh":"lAQEChYZs","tracking_domain":"http:\/\/pixel.facebook.com","retry_ajax_on_network_error":"1","html5_audio":"1","fbid_emoticons":"1"});</script><script>envFlush({"eagleEyeConfig":{"seed":"19vP"}});CavalryLogger=false;window._script_path = "\/profile_page_timeline.php:events";</script><noscript> <meta http-equiv="refresh" content="0; URL=/klubmuzycznyfabrika/?sk=events&amp;_fb_noscript=1" /> </noscript>'

reg = re.compile('envFlush\((?P<json>.*)\)')
fb = reg.search(x)
print fb.groupdict()['json']

---

{"user":"100002298034552","locale":"pl_PL","method":"GET","svn_rev":534081,"vip":"69.171.228.12","static_base":"http:\/\/static.ak.fbcdn.net\/","www_base":"http:\/\/www.facebook.com\/","rep_lag":2,"fb_dtsg":"AQBq8upG","ajaxpipe_token":"AXixBiqWh9DLwJtX","lhsh":"lAQEChYZs","tracking_domain":"http:\/\/pixel.facebook.com","retry_ajax_on_network_error":"1","html5_audio":"1","fbid_emoticons":"1"});</script><script>envFlush({"eagleEyeConfig":{"seed":"19vP"}}