我正在研究具有以下示例资料的熊猫资料框（data_agg_clust）：

           KPIPred
Cluster 
9-11    125.872327
18-20   120.084786
15-17   112.328802
12-14   109.752560
21-23   106.128234

我想使用 matplotlib 创建一个条形图：

import matplotlib.pyplot as plt; plt.rcdefaults()

data_agg_clust.plot.bar(x="Cluster", y="KPIPred", rot=70, title="Predicted Volume of impressions");    
plot.show(block=True);

但不幸的是，我收到了这个错误：

KeyError                                  Traceback (most recent call last)
~/.pyenv/versions/anaconda3-2021.05/envs/jupiter/lib/python3.10/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
   3360             try:
-> 3361                 return self._engine.get_loc(casted_key)
   3362             except KeyError as err:

~/.pyenv/versions/anaconda3-2021.05/envs/jupiter/lib/python3.10/site-packages/pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()

~/.pyenv/versions/anaconda3-2021.05/envs/jupiter/lib/python3.10/site-packages/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: 'Cluster'

The above exception was the direct cause of the following exception

它似乎无法识别“集群”列。我该如何解决这个错误？

uj5u.com热心网友回复：

如果您的资料框的索引有名称，pandas 将通过在列名称下方的一行上打印来直观地区分它。在这种情况下Cluster是您的索引的名称。

最简单的解决方案是不理x会：如果您不提供列名，它将默认为索引：

data_agg_clust.plot.bar(y="KPIPred", rot=70, title="Predicted Volume of impressions")

另一种解决方案是呼叫data_agg_clust.reset_index将索引转换为可用于绘图的列：

data_agg_clust.reset_index().plot.bar(x="Cluster", y="KPIPred", rot=70, title="Predicted Volume of impressions")