仅当元素的总和相等时，如何对元素进行分组？

Question

如果某个日期的购买和出售数量相同，我想合并这些元素，而忽略其余元素，如下例所示。

数据集：

 1/1/09 bought 100 AAPL
 1/1/09 sold 100 AAPL
 1/1/09 bought 35 AAPL
 1/1/09 sold 35 AAPL
 1/1/09 bought 105 AAPL

我希望结果数据框为：

1/1/09 bought 135 AAPL
1/1/09 sold 135 AAPL
1/1/09 bought 105 AAPL

Answer 1

仅按组和求和：

my_var = ['bought','sold','bought','sold','bought']
dollar = [100,100,35,35,105]
date = ['2009-01-01','2009-01-01','2009-01-01','2009-01-01','2009-01-01']
sku = ['AAPL','AAPL','AAPL','AAPL','AAPL']

df = pd.DataFrame({'status':pd.Series(my_var),'dollars':pd.Series(dollar),'date':pd.Series(date),'SKU':pd.Series(sku)})

df.groupby(['SKU','status','date'],as_index = False)['dollars'].sum()