管理库存数据集

Question

早上好，

我有以下数据集：

print(df)

Date        Type of Operation     Quantity         
01/01/17      Order                  5
01/01/17      Sale                   3
02/01/17      Sale                   1
02/01/17      Order                  5

我想创建以下列：

print(df_1)

Date        Type of Operation     Quantity     Actual_Inventory    
01/01/17      Order                  5                5
01/01/17      Sale                   3                2
02/01/17      Sale                   1                1
02/01/17      Order                  5                6

有关如何使用Python和pandas编码的任何建议？谢谢

Answer 1

你可以通过Quantity多个列-1，如果Sale然后使用cumsum：

m = df['Type of Operation'] == 'Sale' 
df['Actual_Inventory'] = df['Quantity'].mask(m, df['Quantity'] * -1).cumsum()

另一种方案：

a = (df['Type of Operation'] == 'Sale').map({True:-1, False:1})
df['Actual_Inventory'] = df['Quantity'].mul(a).cumsum()

---

print (df)
       Date Type of Operation  Quantity  Actual_Inventory
0  01/01/17             Order         5                 5
1  01/01/17              Sale         3                 2
2  02/01/17              Sale         1                 1
3  02/01/17             Order         5                 6