[{'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:df_nodes = test\nlon_min, lon_max = -70.752, -23.483-33\nlat_min, lat_max = -56.382+33, -9.449\nidx_bol = (df_nodes["lon"]>lon_min) &\\\n(df_nodes["lon"]<lon_max) &\\\n(df_nodes["lat"]>lat_min) &\\\n(df_nodes["lat"]<lat_max)\ndf_nodes_bol = df_nodes[idx_bol]\nplt.figure(4, figsize=(64,64))\nm = Basemap(projection=\'merc\',\nllcrnrlat=lat_min,\nurcrnrlat=lat_max,\nllcrnrlon=lon_min,\nurcrnrlon=lon_max,\nlat_ts=35,\nresolution=\'i\')\nm.fillcontinents(color=\'#191919\',lake_color=\'#000000\') # dark grey land, black lakes\nm.drawmapboundary(fill_color=\'#000000\')                # black background\nm.drawcountries(linewidth=0.4, color="w")              # thin white line for country borders\nmxy = m(df_nodes_bol["lon"].tolist(), df_nodes_bol["lat"].tolist())\nm.scatter(mxy[0], mxy[1], s=5, c="#1292db", lw=0, alpha=1, zorder=8)\nplt.title("Bol view of events")\nplt.show()'}, {'role': 'assistant', 'content': 'data_preprocessing'}]