实现决策树

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给出准确率百分比

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validation set准确率0.601946471776109

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select avg(count), min(count)
from (
select userId,count(*) as 'count' from Ratings
group by userid)

平均每个人打分86次，最少打分12次

avg(count)  min(count)
86.2612261991581    12

[gqqnbig]

在main方法里使用

p = mp.Pool()
p.map(classifyUser, userIds)
p.close()
p.join()

不会加快速度，反而会抛出异常

  File "/usr/lib/python3.6/multiprocessing/pool.py", line 44, in mapstar
    return list(map(*args))
  File "DecisionTree.py", line 198, in classifyUser
    cur.executemany('update ValidationRatings set predict=? where userId=? and movieId=?', toDB.tolist())
sqlite3.OperationalError: database is locked

[gqqnbig]

public score 0.58682