.pandas.series 的 str.replace 方法无法按预期工作

Question

我在项目的一个特定阶段遇到了这个问题。

复制以下内容：

import pandas as pd
# Recreated a sample data
data = {
  "FailCodes": ['4301,4090,5003(1)'],  
}
df = pd.DataFrame(data)
# Want to replace the '(1)' with 'p1q'
print(df.FailCodes.str.replace('(1)','p1q'),'\n') # Not giving expected result
# compare to string object method from standard python, which gives desired result
print('4301,4090,5003(1)'.replace('(1)','p1q'),'\n')
# Can get wanted result with following longer code,but would like explanation why first approach giving the unexpected result.
print(df.FailCodes.str.replace('(','p').str.replace(')','q' ))

• 意想不到的结果如：

  430p1q,4090,5003(p1q)

• 预期结果：

  4301,4090,5003p1q

Answer 1

您可能使用旧版本的 Pandas，其中默认参数是

regex=True

（

(1)

是常规模式）。将

regex=False

改为

.str.replace

:

print(df.FailCodes.str.replace("(1)", "p1q", regex=False))

打印：

0    4301,4090,5003p1q
Name: FailCodes, dtype: object