python-3.x - 如何在 Python 中将 int 数据类型的分类数据更改为数值数据

Question

我有一个数据集，其中包含以下列：偏离党派、民主党、与政党在社会问题上的分歧、该受访者的 gss 年份。在 Object 数据类型中可以使用 Partisanship、Democratic、Disagreement with Party on Social Issues 等偏差，因此我必须将它们转换为字符串以将它们编码为数字数据。

'此受访者的 gss 年份'包含从 1970 年到 2000 年的年份，并以 int 数据类型提供，因此我不会将其转换为字符串来执行编码。以下是我正在使用的代码：

 #importing libraires
import pandas as pd
from sklearn.preprocessing import LabelEncoder

#importing data sets
df = pd.read_excel('sec3_data.xlsx')
df.fillna(0, inplace=True)

#converting categorical data to numeric data.
df['Deviation from Partisanship'] = df['Deviation from Partisanship'].astype('str') 
le = preprocessing.LabelEncoder()
df['Deviation from Partisanship'] = le.fit_transform(df['Deviation from Partisanship'])

df['Democrat'] = df['Democrat'].astype('str') 
le = preprocessing.LabelEncoder()
df['Democrat'] = le.fit_transform(df['Democrat'])

df['Disagreement with Party on Social Issues'] = df['Disagreement with Party on Social Issues'].astype('str') 
le = preprocessing.LabelEncoder()
df['Disagreement with Party on Social Issues'] = le.fit_transform(df['Disagreement with Party on Social Issues'])

le = preprocessing.LabelEncoder()
df['gss year for this respondent'] = le.fit_transform(df['gss year for this respondent'])

pd.set_option('display.max_rows', 164)
df

当我运行此代码时，它给了我以下错误：

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
~\Anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   2896             try:
-> 2897                 return self._engine.get_loc(key)
   2898             except KeyError:

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 'gss year for this respondent'

During handling of the above exception, another exception occurred:

KeyError                                  Traceback (most recent call last)
<ipython-input-44-fbfcad1e7a05> in <module>
     13 
     14 le = preprocessing.LabelEncoder()
---> 15 df['gss year for this respondent'] = le.fit_transform(df['gss year for this respondent'])
     16 
     17 pd.set_option('display.max_rows', 164)

~\Anaconda3\lib\site-packages\pandas\core\frame.py in __getitem__(self, key)
   2978             if self.columns.nlevels > 1:
   2979                 return self._getitem_multilevel(key)
-> 2980             indexer = self.columns.get_loc(key)
   2981             if is_integer(indexer):
   2982                 indexer = [indexer]

~\Anaconda3\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   2897                 return self._engine.get_loc(key)
   2898             except KeyError:
-> 2899                 return self._engine.get_loc(self._maybe_cast_indexer(key))
   2900         indexer = self.get_indexer([key], method=method, tolerance=tolerance)
   2901         if indexer.ndim > 1 or indexer.size > 1:

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()

KeyError: 'gss year for this respondent'

知道为什么我会收到此错误吗？

标签： python-3.xscikit-learn

Answer 1

重新发布我自己的评论作为答案，以快速造福他人。

这种类型的错误与引用不存在的 DataFrame 列是一致的。您可以通过 快速检查您引用的列是否存在于 DataFrame 中'<COLUMN_NAME>' in df.columns。如果列存在，它应该返回 True。