def __init__(self, student_id, password, user_agent=None):
self.student_id = student_id<EOL>self.password = password<EOL>self.password_md5 = hashlib.md5(self.password.encode('<STR_LIT:utf-8>')).hexdigest()<EOL>self.post_headers = {'<STR_LIT:Content-Type>': '<STR_LIT>',<EOL>'<STR_LIT>': '<STR_LIT>'}<EOL>self._ua = '<STR_LIT>''<STR_LIT>'<EOL>if user_agent:<EOL><INDENT>self._ua = user_agent<EOL><DEDENT>self.session = self.login()<EOL>
:param student_id: student_id of jw system
:type student_id: str
:param password: password
:type password: str
:param user_agent: User-agent you want to use when requesting the website, default ua is chrome 60.0.3112.113
:type user_agent: str