[{'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:import numpy as np<br>import pandas as pd<br>import keras<br>from sklearn.preprocessing import LabelEncoder, StandardScaler, OneHotEncoder<br>from sklearn.model_selection import train_test_split<br>from sklearn.metrics import f1_score<br>from matplotlib import pyplot as plt<br>import os<br>import re<br>print(os.listdir("../input"))<br>def to_int(obj):<br>    return int(re.sub("[^\\\\d]", \'\', obj))'}, {'role': 'assistant', 'content': 'helper_functions'}]