相关疑难解决方法(0)

我有一个Python pandas DataFrame rpt:

rpt
<class 'pandas.core.frame.DataFrame'>
MultiIndex: 47518 entries, ('000002', '20120331') to ('603366', '20091231')
Data columns:
STK_ID                    47518  non-null values
STK_Name                  47518  non-null values
RPT_Date                  47518  non-null values
sales                     47518  non-null values

我可以过滤库存ID '600809'如下的行:rpt[rpt['STK_ID'] == '600809']

<class 'pandas.core.frame.DataFrame'>
MultiIndex: 25 entries, ('600809', '20120331') to ('600809', '20060331')
Data columns:
STK_ID                    25  non-null values
STK_Name                  25  non-null values
RPT_Date                  25  non-null values
sales                     25  non-null values

我想把一些股票的所有行放在一起,例如['600809','600141','600329'].这意味着我想要这样的语法:

stk_list = ['600809','600141','600329']

rst = rpt[rpt['STK_ID'] in stk_list] # …

我在Pandas中使用布尔索引.问题是为什么声明:

a[(a['some_column']==some_number) & (a['some_other_column']==some_other_number)]

工作正常,而

a[(a['some_column']==some_number) and (a['some_other_column']==some_other_number)]

存在错误？

例:

a=pd.DataFrame({'x':[1,1],'y':[10,20]})

In: a[(a['x']==1)&(a['y']==10)]
Out:    x   y
     0  1  10

In: a[(a['x']==1) and (a['y']==10)]
Out: ValueError: The truth value of an array with more than one element is ambiguous.     Use a.any() or a.all()