You can use the following Python code to extract the JavaScript code.
soup = BeautifulSoup(html)
s=soup.find('script')
js = 'window = {};\n'+s.text.strip()+';\nprocess.stdout.write(JSON.stringify(window.__INITIAL_STATE__));'
with open('temp.js','w') as f:
f.write(js)
The JS code will be written to a file "temp.js". Then you can call node to execute the JS file.
from subprocess import check_output
window_init_state = check_output(['node','temp.js'])
The python variable window_init_state contains the JSON string of the JS object window.__INITIAL_STATE__, which you can parse in python with JSONDecoder.
Example
from subprocess import check_output
import json, bs4
html='''<!DOCTYPE doctype html>
<html lang="en">
<script> window.sessConf = "-2912474957111138742";
/* <sl:translate_json> */
window.__INITIAL_STATE__ = { 'Hello':'World'};
/* </sl:translate_json> */
</script>
</html>'''
soup = bs4.BeautifulSoup(html)
with open('temp.js','w') as f:
f.write('window = {};\n'+
soup.find('script').text.strip()+
';\nprocess.stdout.write(JSON.stringify(window.__INITIAL_STATE__));')
window_init_state = check_output(['node','temp.js'])
print(json.loads(window_init_state))
Output:
{'Hello': 'World'}
nodejsin your system?