[{'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:def one_hot_encode(x):\n"""\nOne hot encode a list of sample labels. Return a one-hot encoded vector for each label.\n: x: List of sample Labels\n: return: Numpy array of one-hot encoded labels\n"""\nb = np.zeros((len(x), 10))\nb[np.arange(len(x)), x] = 1\nreturn b\n"""\nDON\'T MODIFY ANYTHING IN THIS CELL THAT IS BELOW THIS LINE\n"""\ntests.test_one_hot_encode(one_hot_encode)'}, {'role': 'assistant', 'content': 'data_preprocessing'}]