Python 如果列具有字符串，则将值转换为负值

我试图将python中的数量从正转换为负，我有下表：

收付 数量 付款 1233 收据 4561.3 尝试：

印刷品：

收付款金额2
0付款1233.0-1233.0
1收据4561.3 4561.3

试试：

印刷品：

收付款金额2
0付款1233.0-1233.0
1收据4561.3 4561.3

使用df.where，您在正确的轨道上做得非常好

df['Amount 2'] = df.Amount.where(df['Receipt / Payment'].ne('Payment'), -df.Amount)

输入

    Receipt / Payment   Amount
0   Payment             1233.0
1   Receipt             4561.3

    Receipt / Payment   Amount  Amount 2
0   Payment             1233.0  -1233.0
1   Receipt             4561.3  4561.3

输出

    Receipt / Payment   Amount
0   Payment             1233.0
1   Receipt             4561.3

    Receipt / Payment   Amount  Amount 2
0   Payment             1233.0  -1233.0
1   Receipt             4561.3  4561.3

---

你在df.where的正确轨道上做得很好

df['Amount 2'] = df.Amount.where(df['Receipt / Payment'].ne('Payment'), -df.Amount)

输入

    Receipt / Payment   Amount
0   Payment             1233.0
1   Receipt             4561.3

    Receipt / Payment   Amount  Amount 2
0   Payment             1233.0  -1233.0
1   Receipt             4561.3  4561.3

输出

    Receipt / Payment   Amount
0   Payment             1233.0
1   Receipt             4561.3

    Receipt / Payment   Amount  Amount 2
0   Payment             1233.0  -1233.0
1   Receipt             4561.3  4561.3

---

这真是太有魅力了，非常感谢！这真是太有魅力了，非常感谢！