Is there way to get the cookie from browser (console) and use this in python request (user validation)?

I want to crawl a site which uses authentication. After login there are some content that i want to get. I cannot seem to make it work to login with python because it uses authentication token, so i thought there might be a way to log in in browser and observ the request and response to get the cookie which can authenticate the python script to access contens that are hidden behind validation.

I have tried to login with python script but could not get it work.

with requests.Session() as s:
    r = s.get(url, headers=header)

    #r = s.post(url, data=login_data, headers=header)
    print(r.content)
    #s.get(url, data=login_data, headers=header)

login_data = {
    'authenticity_token': '',
    'user[id]': '',
    'user[name]': '',
    'user[pass]': '',
    'commit': 'login'
}