import pandas as pd
import numpy as np
 
df = pd.DataFrame(data={'語文':[50,90,70,78,60],
                        '數(shù)學(xué)':[59,80,60,75,69],
                        '英語':[61,95,65,80,59]},
                  index=['Harry','Andy','Rita','Lee','Jack'])
# 添加'總分'字段
df['總分'] = df['語文'] + df['數(shù)學(xué)'] + df['英語']
# 調(diào)用np.where
# 添加'語文評級','數(shù)學(xué)評級','英語評級'字段
df['語文評級'] = np.where(df['語文'] > 60,'√','×')
df['數(shù)學(xué)評級'] = np.where(df['數(shù)學(xué)'] > 60,'√','×')
df['英語評級'] = np.where(df['英語'] > 60,'√','×')

# 將多列合并為一列,生成'評級合并'字段
df['評級合并'] = df['語文評級'].map(str) + df['數(shù)學(xué)評級'].map(str) + df['英語評級'].map(str)