这是因为
我很困惑……当我从dfocus1中删除列'Focus2'、'Core2'、'Focus3'和'Core3'时，它会在dfocus2 中删除相同的列
为什么？
'''
dfocus1=df
dfocus2=df
dfocus3=df
print('nTable data',dfocus2.info(memory_usage='deep'))
dfocus1.drop(['Focus2','Score2','Focus3','Score3'], axis=1,inplace=True)
print('nTable data',dfocus2.info(memory_usage='deep'))
'''
dfocus1和dfocus2指向同一个对象(df(。
创建df的copy，然后删除列：
dfocus1=df.copy()
dfocus2=df.copy()