[{'role': 'system', 'content': "You are an expert in machine learning and your task is to classify the code snippets into categories from the provided list of categories. List of categories: ['helper_functions', 'load_data', 'data_exploration', 'data_preprocessing', 'evaluation', 'modelling', 'prediction', 'result_visualization', 'save_results', 'comment_only']"}, {'role': 'user', 'content': "Identify to which category the provided code belongs and assign the code snippet to at least 1 but up to 5 categories based on the probabilities, ignore if the probability of the category is negligible. Strictly provide your response as a list. Avoid providing any additional information, commentary, or personal opinions.\\nPython Code:def divide_on(df, char):\n    \n    # iterate over text column of DataFrame, splitting at each occurrence of char\n\n    sentences = []\n    # let's split the data into senteces\n    for i, row in df.iterrows():\n        \n        # skip the intro lines of the speech\n        for sentence in row['text'].split(char)[starts[i]:]:\n            sentences.append([row['president'], sentence])\n\n    df = pd.DataFrame(sentences, columns=['president', 'text'])\n    \n    return df[df['text'] != '']"}, {'role': 'assistant', 'content': "['data_preprocessing']"}]