python - Pandas 数据框替换列的多个子字符串

Question

下面是代码

import pandas as pd

df = pd.DataFrame({'A': ['$5,756', '3434', '$45', '1,344']})

pattern = ','.join(['$', ','])

df['A'] = df['A'].str.replace('$|,', '', regex=True)
print(df['A'])

我试图删除每次出现的“$”或“,”...所以我试图用空白替换..

但它只是替换，

我得到的输出

0    $5756
1     3434
2      $45
3    1344$

应该是

0    5756
1     3434
2      45
3    1344

我做错了什么

感谢任何帮助

谢谢

Answer 1

使用:

import pandas as pd

df = pd.DataFrame({'A': ['$5,756', '3434', '$45', '1,344']})
df['A'] = df['A'].str.replace('[$,]', '', regex=True)
print(df)

输出

      A
0  5756
1  3434
2    45
3  1344

问题是字符 $ 在正则表达式中有特殊含义。来自documentation (强调我的):

$
Matches the end of the string or just before the newline at the endof the string, and in MULTILINE mode also matches before a newline.foo matches both ‘foo’ and ‘foobar’, while the regular expression foo$matches only ‘foo’. More interestingly, searching for foo.$ in'foo1\nfoo2\n' matches ‘foo2’ normally, but ‘foo1’ in MULTILINE mode;searching for a single $ in 'foo\n' will find two (empty) matches: onejust before the newline, and one at the end of the string.mode;searching for a single $ in 'foo\n' will find two (empty) matches: onejust before the newline, and one at the end of the string.

因此您需要转义字符或将其放入字符类中。

作为替代用途:

df['A'].str.replace('\$|,', '', regex=True)  # note the escaping \