根据其他两列向新列添加值

Question

我有一个像这样的数据框架。我已经创建了3个新列，这些列将接受其他列的值。我希望函数列分开，并为每个函数获取每个用户的总时数。

 User         Function          Total hours   Damage Processing problem solve damages sweeper
 schae      Damage Processing      9.36
 Julie      Problem solve          9.70
 John       sweeper                18.9
 Dan       Damages                 1.83
 Dan       Damages                 1.83
 Julie     Damages                 1.83
 Dan       Problem solve           1.83

预期的输出将类似于

 User         Function          Total hours   Damage Processing  problem solve damages  sweeper
 schae     Damage Processing       9.36          9.36
 Julie     Problem solve           9.70                            9.70
 John      sweeper                 18.9                                                  18.9
 Dan       Damages                 1.83                                        1.83                                 
 Dan       sweeper                 1.83                                                  1.83
 Julie     Damages                 1.83                                        1.83
 Dan       Problem solve           1.83                            1.83

我想到了pd.melt，但它抛出了一个不存在的错误值var

res = pd.melt(result,id_vars = ['Function'],value_vars=['Total hours'])

Answer 1

下面是一种使用get_dummies和df.assign的方法

out = (df[['User','Function','Total hours']].assign(**pd.get_dummies(df['Function'])
       .mul(df['Total hours'],axis=0).replace(0,np.nan)))
print(out)

    User           Function  Total hours  Damage Processing  Damages  \
0  schae  Damage Processing         9.36               9.36      NaN   
1  Julie      Problem solve         9.70                NaN      NaN   
2   John            sweeper        18.90                NaN      NaN   
3    Dan            Damages         1.83                NaN     1.83   
4    Dan            Damages         1.83                NaN     1.83   
5  Julie            Damages         1.83                NaN     1.83   
6    Dan      Problem solve         1.83                NaN      NaN   

   Problem solve  sweeper  
0            NaN      NaN  
1           9.70      NaN  
2            NaN     18.9  
3            NaN      NaN  
4            NaN      NaN  
5            NaN      NaN  
6           1.83      NaN 

Answer 2

for i in range(len(df)):
    col = df.loc[i]['Function']
    df.at[i, col] = df.xs(i)['Total hours']
    print(col)

试试这个！变量col找到要为其插入Total hours值的列。