how did you get vocabulary at first?

i am developing you code to android and what is wonder for me is after make _login, self.vocabulary is filled. but i don't know how.
can you explain me more? i am new at python!
and what do you send as session?

It is not filled automatically after login. It is filled as soon as you access the variable, because it is a method not a variable... See

Duolingo/duolingo.py

Line 539 in 9e552ba

def get_vocabulary(self, language_abbr=None):

this function gets mapped to the property self.vocabulary