def function(params): #这里包含函数实现代码，至少3行 for code in df['code'].unique(): # Select rows with the current stock code df_code = df[df['code'] == code] # Calculate MACD indicator using the closing price exp1 = df_code['close'].ewm(span=12, adjust=False).mean() exp2 = df_code['close'].ewm(span=26, adjust=False).mean() macd = exp1 - exp2 # Calculate the signal line as the 9-day EMA of the MACD signal = macd.ewm(span=9, adjust=False).mean() # Calculate the MACD histogram as the difference between the MACD and signal line macd_hist = macd - signal # Add MACD indicators to the DataFrame df.loc[df['code'] == code, 'macd'] = macd df.loc[df['code'] == code, 'macdsignal'] = signal df.loc[df['code'] == code, 'macdhist'] = macd_hist