在某些情况下，如何将一列乘以一个数字？

Question

我有以下数据框，名称为 a.

symbol  position    strategy    industry    Fund    EX Date Pay Date    Record Date Type    Net Rate    Gross Rate  Product Type
0   7203    44000.00    L   Trans.Equip.    59107   2021/03/30  2021/05/28  2021/03/31  Cash Dividend   102.00  120.00  EQ
1   6758    28500.00    L   Elec. App.  59107   2021/03/30  2021/06/04  2021/03/31  Cash Dividend   25.00   30.00   EQ
2   4063    12500.00    L   Chemicals   59107   2021/03/30  2021/06/29  2021/03/31  Cash Dividend   110.00  130.00  EQ
16  8306    256000.00   L   Banks   59107   2021/03/30  2021/06/30  2021/03/31  Cash Dividend   11.00   13.00   EQ
17  3003    115000.00   L   Real Estate 59107   NaN NaN NaN <NA>    nan nan <NA>

现在我想添加一个新列，为我提供 position*Rate 然后当我的“策略”是“S”时，我想将新列乘以 (-1) 但是这段代码给了我一个错误

a['Earning'] = a['position']*a['Net Rate']

def short(row):
    if row["strategy"] == 'S':
        return row['Earning'] *(-1)

a["final_earning"] = a.apply(short, axis=1)

错误的最后一行是

TypeError: boolean value of NA is ambiguous

如何获得“最终收入”。提前谢谢。

Answer 1

这应该适合你：

import numpy as np

a['Earning'] = a["position"].mul(a["Net Rate"])

def short(row):
    if row["strategy"] == 'S' and not np.isnan(row["Earning"]):
        return row['Earning'] * (-1)
    return np.nan

a["final_earning"] = a.apply(short, axis=1)

Pandas mul 函数为您处理 nan 值。

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