Pandas多列值合并成一列的实现

import pandas as pd
import numpy as np
 
df = pd.DataFrame(data={'语文':[50,90,70,78,60],
                        '数学':[59,80,60,75,69],
                        '英语':[61,95,65,80,59]},
                  index=['Harry','Andy','Rita','Lee','Jack'])
# 添加'总分'字段
df['总分'] = df['语文'] + df['数学'] + df['英语']
# 调用np.where
# 添加'语文评级','数学评级','英语评级'字段
df['语文评级'] = np.where(df['语文'] > 60,'√','×')
df['数学评级'] = np.where(df['数学'] > 60,'√','×')
df['英语评级'] = np.where(df['英语'] > 60,'√','×')

# 将多列合并为一列,生成'评级合并'字段
df['评级合并'] = df['语文评级'].map(str) + df['数学评级'].map(str) + df['英语评级'].map(str)