login_token = '/api.php?action=query&format=xml&prop=&list=&meta=tokens&type=login'
r = requests.get (wiki + login_token)
logintoken = re.compile (r'(?<=logintoken=["])[^"]+(?=["])')
logintoken = logintoken.search (r.text).group()

user="---"
password="---"
login = '/api.php?action=login&format=xml&lgname=' + user + '&lgpassword=' + password + '&lgtoken=' + logintoken
r = requests.post (wiki + login)
print (r.text)