mean_dependency_depth.py

#!/usr/bin/env python3

from collections import defaultdict
from math import log

import sys

depths_by_target = defaultdict(list)

with open(sys.argv[1]) as f:
    for line in f:
        bcvw, text, sword = line.strip().split()
        target = bcvw[:5]
        item = sword
        depth = len(item.split("-"))
        depths_by_target[target].append(depth)

for target, depths in depths_by_target.items():
    print(int(1000 * sum(depths) / len(depths)), target)