根据来自另一个表的多列在一个表中创建一列[python]

时间:2019-08-20 14:46:27

标签: python pandas numpy csv

我正在创建一个csv表,其中包含我所有订单的信息。现在我想卖掉那些物品,但是我想根据物品的价格增加额外的附加费。我创建了一个带有surcharge的新表,我在其中有名为'from'和'to'的列,在这些列中我必须比较商品价格,然后在销售价格中包含正确的附加费。

但是我无法做到这一点。我尝试了不同的方法,但似乎没有一种有效。任何帮助都很好:)

我的桌子看起来像这样:

    OrderNo      NetPerPiece costsDividedPerOrder  HandlingPerPiece

0  7027514279        44.24     0.008007          0.354232

1  7027514279        15.93     0.008007          0.127552

2  7027514279        15.93     0.008007          0.127552

3  7027514279        15.93     0.008007          0.127552

4  7027514279        15.93     0.008007          0.127552
surcharges = {'surcharge': [0.35, 0.25, 0.2, 0.15, 0.12, 0.1],
'from': [0, 20, 200, 500, 1500, 5000], 
'to' : [20, 200, 500, 1500, 5000,1000000000] }
surchargeTable = DataFrame(surcharges, columns=['surcharge', 'from', 'to'])


productsPerOrder['NetPerpieceSale'] = numpy.where(((productsPerOrder['NetPerPiece'] >= surchargeTable['from']) & (productsPerOrder['NetPerPiece'] < surchargeTable['to'])), surchargeTable['surcharge'])


#I also tried this:

for index, row in productsPerOrder.iterrows():
        if row['NetPerPiece'] >= surchargeTable['from'] & row['NetPerPiece'] < surchargeTable['to']:
                productsPerOrder.loc[index,'NerPerPieceSale'] = surchargeTable.loc[row,'NetPerPieceSale'].values(0)

我希望它看起来像这样:

 OrderNo   NetPerPiece costsDividedPerOrder  HandlingPerPiece NetPerPieceSale

0  7027514279   44.24           0.008007          0.354232    0.25

1  7027514279   15.93           0.008007          0.127552    0.35

2  7027514279   15.93           0.008007          0.127552    0.35

3  7027514279   15.93           0.008007          0.127552    0.35

4  7027514279   15.93           0.008007          0.127552    0.35

提醒一下,包含项目的文件要大得多,我只显示了csv列表的开头。因此表的长度不同

SurchargeTable看起来像这样:

 surcharge  from          to
0       0.35     0          20
1       0.25    20         200
2       0.20   200         500
3       0.15   500        1500
4       0.12  1500        5000
5       0.10  5000  1000000000

3 个答案:

答案 0 :(得分:2)

另一种方法是使用implementation 'org.springframework.boot.experimental:spring-boot-starter-data-r2dbc:0.1.0.BUILD-SNAPSHOT' pd.IntervalIndex

map

输出:

# Create IntervalIndex on surchageTable dataframe
surchargeTable = surchargeTable.set_index(pd.IntervalIndex.from_arrays(surchargeTable['from'],
                                                                       surchargeTable['to']))

#Use map to pd.Series created from surchargeTable IntervalIndex and surcharge column.
productsPerOrder['NetPerPieceSale'] = productsPerOrder['NetPerPiece'].map(surchargeTable['surcharge'])

productsPerOrder

答案 1 :(得分:1)

创建一个函数来计算附加费,然后使用.apply将其应用到“ NetPerPiece”行。

import pandas as pd
df = pd.read_csv('something.csv')   

def get_surcharges(x):
    to = [0, 20, 200, 500, 1500, 5000] 
    fr = [20, 200, 500, 1500, 5000,1000000000]
    surcharges = [0.35, 0.25, 0.2, 0.15, 0.12, 0.1]
    rr = list(zip(to, fr, surcharges))
    price = [r[2] for r in rr if x > r[0] and x <r[1]]
    return price[0]

df['NetPerpieceSale'] = df['NetPerPiece'].apply(lambda x: get_surcharges(x))

print(df)

这将输出:

      OrderNo  NetPerPiece  costsDividedPerOrder  HandlingPerPiece  NetPerpieceSale
0  7027514279        44.24              0.008007          0.354232             0.25
1  7027514279        15.93              0.008007          0.127552             0.35
2  7027514279        15.93              0.008007          0.127552             0.35
3  7027514279        15.93              0.008007          0.127552             0.35
4  7027514279        15.93              0.008007          0.127552             0.35

不带for循环的选项(有点冗长):

def get_surcharges(x):
    if x > 0:
        if x > 20:
            if x > 200:
                if x > 500:
                    if x > 1500:
                        if x > 5000:
                            return 0.1
                        else:
                            return 0.12
                    else:
                        return 0.15
                else:
                    return 0.2
            else:
                return 0.25
        else:
            return 0.35

答案 2 :(得分:0)

使用上述NetPerPieceScale的计算,只需在现有数据框中添加一列
或者您可以将计算结果保存到这样的数据框中:
net=pd.DataFrame(NetPerPieceScale, columns=['NetPerPieceScale '])

只需将其连接到现有数据框,您将在1个表中拥有所有内容