Question

我试图在这个简单的表格上做一些修饰，即设置一个 2 级索引，以便 SalePrice 将成为均值和中位数的主要标签，但在下面将分别有均值和中位数。我想要类似以下内容：

              SalePrice
LandSlope   Mean   Median
 *data*    *data*  *data*

我这样做的尝试如下：

#houseprices.info()
sloprice = houseprices[['LandSlope', 'SalePrice']]
sloprice = sloprice.copy()
sloprice_mean = sloprice.groupby(by='LandSlope').mean()
sloprice_mean.rename(columns={'SalePrice': 'Mean'})
sloprice_med = sloprice.groupby(by='LandSlope').median()
sloprice_med.rename(columns={'SalePrice': 'Median'})
sloprice = pd.merge(sloprice_mean, sloprice_med, on='LandSlope')
index = pd.MultiIndex(levels=[['SalePrice'], ['Mean', 'Median']], codes=[[0, 0], [0, 1]])
sloprice.columns.rename(index)
sloprice

我收到的错误信息：

TypeError                                 Traceback (most recent call last)
<ipython-input-34-490152c77e52> in <module>
      8 sloprice = pd.merge(sloprice_mean, sloprice_med, on='LandSlope')
      9 index = pd.MultiIndex(levels=[['SalePrice'], ['Mean', 'Median']], codes=[[0, 0], [0, 1]])
---> 10 sloprice.columns.rename(index)
     11 sloprice

~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in rename(self, name, inplace)
   1371         TypeError: Must pass list-like as `names`.
   1372         """
-> 1373         return self.set_names([name], inplace=inplace)
   1374 
   1375     # --------------------------------------------------------------------

~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in set_names(self, names, level, inplace)
   1318         else:
   1319             idx = self._shallow_copy()
-> 1320         idx._set_names(names, level=level)
   1321         if not inplace:
   1322             return idx

~\anaconda3\lib\site-packages\pandas\core\indexes\base.py in _set_names(self, values, level)
   1239         for name in values:
   1240             if not is_hashable(name):
-> 1241                 raise TypeError(f"{type(self).__name__}.name must be a hashable type")
   1242         self._name = values[0]
   1243 

TypeError: Index.name must be a hashable type

在 Pandas MultiIndex 文档中对代码参数的描述不清楚，这不是可选的，所以我做了一些谷歌搜索以更好地理解 codes 是什么以及它有什么用处，但是我如何'我把它放在语法中似乎是错误的。如果您能解释我做错了什么以及如何实现我最初想要的效果，我将不胜感激。

Pandas 添加新的索引级别，MultiIndex 错误

0 个答案: