[{'role': 'system', 'content': "You are an expert in machine learning and your task is to classify code snippets into one of the following categories: ['helper_functions', 'load_data', 'data_exploration', 'data_preprocessing', 'evaluation', 'modelling', 'prediction', 'result_visualization', 'save_results', 'comment_only']."}, {'role': 'user', 'content': 'Identify the single most appropriate category to which the provided code belongs. Provide your response as a single category label without any additional information, commentary, or personal opinions.\\nPython Code:squaresDF = spark.createDataFrame(sc.parallelize(range(1, 6))\n.map(lambda i: Row(single=i, double=i ** 2)))\nsquaresDF.write.parquet("/tmp/test_table/key=1")\ncubesDF = spark.createDataFrame(sc.parallelize(range(6, 11))\n.map(lambda i: Row(single=i, triple=i ** 3)))\ncubesDF.write.parquet("/tmp/test_table/key=2")\nmergedDF = spark.read.option("mergeSchema", "true").parquet("/tmp/test_table")\nmergedDF.printSchema()'}, {'role': 'assistant', 'content': 'data_preprocessing'}]