import pandas as pdbooks  = pd.read_excel('e:/Books.xlsx',index_col='ID') for i in books.index:    books['Price'].at[i]=books['ListPrice'].at[i]*books['Discount'].at[i]print(books)

 

import pandas as pdbooks  = pd.read_excel('e:/Books.xlsx',index_col='ID')books['ListPrice']=books['ListPrice'].apply(lambda x:x+2)  #也可定义函数 print(books)