[英]JSON to Spark RDD in Python
我对Spark非常陌生,并且已经尝试了一段时间以让Spark理解我的JSON输入,但是我没有进行管理。 总之,我正在使用Spark的ALS算法来提出建议。 当我提供一个csv文件作为输入时,一切正常。 但是,我的输入实际上是一个json,如下所示:
all_user_recipe_rating = [{'rating': 1, 'recipe_id': 8798, 'user_id': 2108}, {'rating': 4, 'recipe_id': 6985, 'user_id': 4236}, {'rating': 4, 'recipe_id': 13572, 'user_id': 2743}, {'rating': 4, 'recipe_id': 6312, 'user_id': 3156}, {'rating': 1, 'recipe_id': 12836, 'user_id': 768}, {'rating': 1, 'recipe_id': 9237, 'user_id': 1599}, {'rating': 2, 'recipe_id': 16946, 'user_id': 2687}, {'rating': 2, 'recipe_id': 20728, 'user_id': 58}, {'rating': 4, 'recipe_id': 12921, 'user_id': 2221}, {'rating': 2, 'recipe_id': 10693, 'user_id': 2114}, {'rating': 2, 'recipe_id': 18301, 'user_id': 4898}, {'rating': 2, 'recipe_id': 9967, 'user_id': 3010}, {'rating': 2, 'recipe_id': 16393, 'user_id': 4830}, {'rating': 4, 'recipe_id': 14838, 'user_id': 583}]
ratings_RDD = self.spark.parallelize(all_user_recipe_rating)
ratings = ratings_RDD.map(lambda row:
(Rating(int(row['user_id']),
int(row['recipe_id']),
float(row['rating']))))
model = self.build_model(ratings)
这是我在看到一些示例后想到的,但这是我得到的:
MatrixFactorizationModel: User factor is not cached. Prediction could be slow.
16/12/21 03:54:53 WARN MatrixFactorizationModel: Product factor does not have a partitioner. Prediction on individual records could be slow.
16/12/21 03:54:53 WARN MatrixFactorizationModel: Product factor is not cached. Prediction could be slow.
16/12/21 03:54:53 WARN MatrixFactorizationModelWrapper: User factor does not have a partitioner. Prediction on individual records could be slow.
和
File "/usr/local/spark/python/pyspark/mllib/recommendation.py", line 147, in <lambda>
user_product = user_product.map(lambda u_p: (int(u_p[0]), int(u_p[1])))
TypeError: int() argument must be a string or a number, not 'Rating'
有人可以帮我吗? :) 谢谢!
好,
您的错误是由于一件事而发生的。
您所遭受的此异常是关于ALS函数的 predictAll
函数 。
这里的问题是,您正在尝试将Rating对象发送给需要接收RDD<int, int>
的函数
我获取了您的代码,并构建了所需的代码:
>>> from pyspark.mllib.recommendation import Rating
>>> ratings = ratings_RDD.map(lambda row:
... (Rating(int(row['user_id']),
... int(row['recipe_id']),
... float(row['rating']))))
>>> model = ALS.trainImplicit(ratings, 1, seed=10)
>>> to_predict = spark.parallelize([[2108, 16393], [583, 20728]])
>>> model.predictAll(to_predict).take(2)
[Rating(user=583, product=20728, rating=0.0741161997082127), Rating(user=2108, product=16393, rating=0.05669039815320609)]
您的JSON没错,在调用predictAll
,您遇到的问题是您发送的是Rating
对象而不是RDD<int, int>
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