[{'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:features = ['Email_Campaign_Type', 'Email_Source_Type', 'Email_Type',\n'Subject_Hotness_Score', 'Time_Email_sent_Category', 'Word_Count']\ntarget = ['Customer_Location']\nle = LabelEncoder()\ndata1 = data[features + target].loc[data['Customer_Location'].isnull() == False]\nX = data1[features]\ny = data1[target]\ny = le.fit_transform(y)\nprint(len(X), y)"}, {'role': 'assistant', 'content': 'data_preprocessing'}]