奥运奖牌积分制，金牌3枚，银牌2枚，布朗茨1枚

Question

写一个函数来创建一个叫做“Points”的序列，这个序列是一个加权值，其中每个金牌（Gold.2）代表3分，银牌（Silver.2）代表2分，铜牌（Bronze.2）代表1分。函数应该只返回您创建的列（一个系列对象）。在

此函数应返回一个名为Points的序列，长度为146

我是python和pandas的新手，我不知道这段代码是否正确，但我得到了一个关键错误

KeyError: "['Gold.2' 'Silver.2' 'Bronze.2'] not in index" for this code: 

import pandas as pd

df = pd.read_csv('olympics.csv', index_col=0, skiprows=1)

def answer_four():

    df['Points'] = df[(df[['Gold.2','Silver.2','Bronze.2']], [3,2,1])]
    #df[['Gold.2','Silver.2','Bronze.2']].apply(lambda x:(x,[3,2,1]))
    olympic_points_df = df[['Points']]


    return olympic_points_df

answer_four()

如果有任何帮助，我们将不胜感激。在

Answer 1

一些类似的东西会起作用

def answer_four():
    df['Points'] = df['Gold.2']*3 + df['Silver.2']*2 + df['Bronze.2'] 
    return df['Points']

Answer 2

def answer_four():
    df['Points'] = df['Gold.2']*3 + df['Silver.2']*2 + df['Bronze.2']
    Points = pd.Series(df['Points'],index=df.index)
    return Points

answer_four()