ValueError: You need to provide a voter account

Solution:

vote(self, identifier, weight, account=None):

Vote function requires the account name, so modify the code as shown below,

s.vote('@benniebanana/creating-your-first-program-on-the-steemit-network-using-steem-python-beginnermode-tutorial', 100.0,'xyz')

where 'xyz' is the voter's account name.