小编py *_* me的帖子

我正在尝试向 Panda 数据集添加一个新列。这个新列 df['Year_Prod'] 派生自另一个 df['title'] 我从中提取年份。

数据示例：

country    designation     title
Italy      Vulkà Bianco    Nicosia 2013 Vulkà Bianco (Etna)         
Portugal   Avidagos        Quinta dos Avidagos 2011 Avidagos Red (Douro)      

代码：

import re

import pandas as pd

df=pd.read_csv(r'test.csv', index_col=0)

df['Year_Prod']=re.findall('\\d+', df['title'])

print(df.head(10))

我收到以下错误：

 File "C:\Python37\lib\site-packages\pandas\core\frame.py", line 3119, in __setitem__self._set_item(key, value)

  File "C:\Python37\lib\site-packages\pandas\core\frame.py", line 3194, in _set_item value = self._sanitize_column(key, value)

  File "C:\Python37\lib\site-packages\pandas\core\frame.py", line 3391, in _sanitize_column value = _sanitize_index(value, self.index, copy=False)

  File "C:\Python37\lib\site-packages\pandas\core\series.py", line 4001, in _sanitize_index raise ValueError('Length of values does …