列表理解以奇怪的格式显示数字

Question

我有一个这样的 pandas DataFrame：

Transaction	Transaction Amount
Deposit	10.00
Dividend	0.9
Taxes	0.04

我正在应用这样的列表理解：

df['Tax'] = ['0' if i == "Deposit" or i == "Dividend" else df['Transaction Amount'] for i in df['Transaction']]


df['Net Amount'] = [df['Transaction Amount'] if i == "Deposit" or i == "Dividend" else -1 * df['Tax'] for i in df['Transaction']]

然而，对于这两种情况，我都得到了这样一个奇怪的输出：“0 1.00 1 1000.00 2 1000.00 3...”

交易金额是一个 float64，我试着把它变成字符串，看看是否能解决问题，但我总是得到同样的结果。

Answer 1

尝试使用 np.where 而不是列表理解。

import numpy as np
df['Tax'] = np.where(df['Transaction'].isin(['Deposit', 'Dividend']),
                     0 ,df['Transaction Amount'])

df['Net Amount'] = np.where(df['Transaction'].isin(['Deposit', 'Dividend']), 
                            df['Transaction Amount'], -1*df['Tax'])

输出：

  Transaction  Transaction Amount   Tax  Net Amount
0     Deposit               10.00  0.00       10.00
1    Dividend                0.90  0.00        0.90
2       Taxes                0.04  0.04       -0.04

列表理解以奇怪的格式显示数字

List comprehension showing numbers in a weird format

python

list-comprehension

dataframe

pandas