[{'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:team_stat = team_stat.groupby('team_api_id').mean().reset_index()\nmatches = pd.merge(left=matches, right=teams, how='left',\nleft_on='home_team_api_id', right_on='team_api_id')\nmatches = pd.merge(left=matches, right=teams, how='left',\nleft_on='away_team_api_id', right_on='team_api_id')\nmatches = matches.drop(['country_id','league_id','id_y', 'team_api_id_x',\n'team_fifa_api_id_x', 'team_short_name_x', 'id',\n'team_api_id_y', 'team_fifa_api_id_y',\n'match_api_id', 'team_short_name_y'], axis=1)\nmatches.rename(columns={'id_x':'match_id', 'team_long_name_x':'home_team',\n'team_long_name_y':'away_team'}, inplace=True)\nmatches = pd.merge(left=matches, right=team_stat, how='left',\nleft_on= 'home_team_api_id', right_on='team_api_id')\nmatches = matches.drop(['team_api_id','team_fifa_api_id','id'], axis = 1)\nmatches = pd.merge(left=matches, right=team_stat, how='left',\nleft_on= 'away_team_api_id', right_on='team_api_id')\nmatches = matches.drop(['team_api_id','team_fifa_api_id','id'], axis = 1)\n'''\n- Win = 1\n- Lose = -1\n- Draw = 0\n'''\nres = pd.DataFrame(np.zeros((len(matches),2)))\nfor i in range(len(matches)):\nif matches['home_team_goal'][i] > matches['away_team_goal'][i]:  # in case of win\nres.iloc[i][1] = 1\nelif matches['home_team_goal'][i] < matches['away_team_goal'][i]:  # in case of lose\nres.iloc[i][1] = -1\nelse:\nres.iloc[i][1] = 0  # in case of draw\nres_colnames = ['match_id','label']\nres.columns = res_colnames\nres['match_id'] = matches['match_id']\nmatches = pd.merge(left=matches, right=res, how='left', left_on='match_id',\nright_on='match_id')\nteampoint =matches.groupby(['home_team']).sum()['label']\nteamlist = pd.DataFrame(teampoint.index)  # Sort out teams from the matches' list\ncitylist = pd.DataFrame(['London', 'Birmingham','Birmingham','Blackburn with Darwen','Blackppol'\n,'Bolton','Bournemouth','Burnley','Cardiff','London','London','Liverpool',\n'London','Hull','Leicester','Liverpool','Manchester','Manchester','Middlesbrough',\n'Newcastle','Norwich','Portsmouth','London','Reading','Southamton',\n'Stock-on-trent','Sunderland','Swansea','London','Watford','West bromwich',\n'West ham', 'Wigan','Wolverhampton'])\nteam_city = pd.concat([teamlist,citylist],axis=1)\nteam_city.columns = ['team','city']\ncordlist = {'London':(51.5073509,-0.127758299),\n'Birmingham':(52.48624299999999,-1.8904009999999971),\n'Blackburn with Darwen':(53.748575,-2.487528999999995),\n'Blackpool':(53.8175053,-3.035674800000038),\n'Bolton':(53.57686469999999,-2.4282192000000578),\n'Bournemouth':(50.719164,-1.8807689999999866),\n'Burnley':(53.7892877,-2.2405034999999316),\n'Cardiff':(51.48158100000001,-3.1790899999999738),\n'Liverpool':(53.4083714,-2.9915726000000404),\n'Hull':(53.7456709,-0.3367412999999715),\n'Leicester':(52.6368778,-1.1397591999999577),\n'Manchester':(53.4807593,-2.2426305000000184),\n'Middlesbrough':(54.574227,-1.234956000000011),\n'Newcastle':(54.978252,-1.6177800000000389),\n'Norwich':(52.6308859,1.2973550000000387),\n'Portsmouth':(50.8197675,-1.0879769000000579),\n'Reading':(51.4542645,-0.9781302999999753),\n'Southamton':(50.9097004,-1.404350900000054),\n'Stock-on-trent':(53.00266799999999,-2.179403999999977),\n'Sunderland':(54.90686899999999,-1.3838009999999485),\n'Swansea':(51.62143999999999,-3.9436459999999443),\n'Watford':(51.65648899999999,-0.39031999999997424),\n'West bromwich':(52.517664,-1.9951590000000579),\n'West ham':(51.538265,0.014525000000048749),\n'Wigan':(53.5450645,-2.6325074000000086),\n'Wolverhampton':(52.586973,-2.128820000000019)}"}, {'role': 'assistant', 'content': 'data_preprocessing'}]