[{'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:trainingData = read_csv('../input/train.csv') \ntrainingData=trainingData[['Id','Pregnancies','Glucose','BloodPressure','SkinThickness','Insulin','BMI','DiabetesPedigreeFunction','Age','Outcome']]\ntestingData = read_csv('../input/test.csv')\ntestingData=testingData[['Id','Pregnancies','Glucose','BloodPressure','SkinThickness','Insulin','BMI','DiabetesPedigreeFunction','Age']]\ntrainingFeatures = trainingData.iloc[:, :-1]\ntrainingLabels = trainingData.iloc[:, -1]\nimputer = SimpleImputer(missing_values=0,strategy='median')\ntrainingFeatures = imputer.fit_transform(trainingFeatures)\ntrainingFeatures = pd.DataFrame(trainingFeatures)\ntrainingFeatures.columns=['Id','Pregnancies','Glucose','BloodPressure','SkinThickness','Insulin','BMI','DiabetesPedigreeFunction','Age']\ntestingData = imputer.transform(testingData)\ntestingData = pd.DataFrame(testingData)\ntestingData.columns=['Id','Pregnancies','Glucose','BloodPressure','SkinThickness','Insulin','BMI','DiabetesPedigreeFunction','Age']\ntrainingFeatures2 = trainingFeatures.drop(['Id'], axis=1)"}, {'role': 'assistant', 'content': 'data_preprocessing'}]