如何从字符串python pandas中提取数字和字符？

Question

我有一个混合数字数据和字符数据的数据集。我只想提取数值数据和字母“ w”（我不需要'2 x hdmi | 2 x usb'....）。

在这种情况下（20 W，30W等）。 感谢您的帮助

v=['2 x HDMI | 2 x USB', '20 W Speaker Output', '10 W Speaker Output',
       '20 W Speaker Output', '20 W Speaker Output',
       '20 W Speaker Output', '20 W Speaker Output', '20 Speaker Output',
       '20 W Speaker Output', '20 W Speaker Output',
       '30 W Speaker Output', '20 W Speaker Output',
       '20 W Speaker Output', '2 x HDMI | 2 x USB', '20 W Speaker Output',
       '20 Speaker Output', '24 W Speaker Output', '20 W Speaker Output']

df=pd.DataFrame({"col_1":v})

Answer 1

您可以使用正则表达式和一些列表理解骗局来获得所需的东西：

import re
import pandas as pd

v=['2 x HDMI | 2 x USB', '20 W Speaker Output', '10 W Speaker Output',
       '20 W Speaker Output', '20 W Speaker Output',
       '20 W Speaker Output', '20 W Speaker Output', '20 Speaker Output',
       '20 W Speaker Output', '20 W Speaker Output',
       '30 W Speaker Output', '20 W Speaker Output',
       '20 W Speaker Output', '2 x HDMI | 2 x USB', '20 W Speaker Output',
       '20 Speaker Output', '24 W Speaker Output', '20 W Speaker Output']

df=pd.DataFrame({"col_1":[v.group(0) for v in [re.search('\d+\s?[Ww]', v) for v in v] if v]})

...导致：

>>> df
   col_1
0   20 W
1   10 W
2   20 W
3   20 W
4   20 W
5   20 W
6   20 W
7   20 W
8   30 W
9   20 W
10  20 W
11  20 W
12  24 W
13  20 W

Answer 2

尝试：

import re
for x in v:
    ms = re.compile(r'\d+\s[wW]')
    m = re.search(ms, x)
    print(m.group())

Answer 3

print(df['col_1'].str.extract(r'(\d+ [W])*'))

上述提取方法与正则曲目，将按预期过滤，然后清除NAN值。