example of sampling from a distribution vector

util.py

def sample_from_distribution(distribution_vector):
    ''' samples from a provided distribution (e.g. for choosing an action from a VW returned distribution vector) '''
    
    probabilities = list(map(float, distribution_vector))
    actions = range(1,len(distribution_vector)+1) # VW actions are 1-indexed not zero indexed
    
    assert(len(actions) == len(probabilities))
   
    s = choices(actions, probabilities)  # https://docs.python.org/3/library/random.html#random.choices 
    action = s[0]
    
    probability = probabilities[actions.index(action)] 
    
    return (action, probability)