Average Agreement, Attempt 2

average_agreement.py

def average_agreement(list1, list2, max_depth):
 
    ### NEW CODE ###
    # Empty lists evaluate to false.
    if (not list1) or (not list2):
        return 0.0
 
    agreements = []
     
    for depth in range(1, max_depth+1):
        set1 = set(list1[:depth])
        set2 = set(list2[:depth])
         
        intersection = set1 & set2
         
        agreements.append(2 * len(intersection) / (len(set1) + len(set2)))
     
    return sum(agreements) / len(agreements)