【发布时间】：2021-05-01 19:26:43
【问题描述】：
我正在尝试运行此代码： （这会将 MNIST 数据集下载到 %HOME 目录！）
from sklearn.datasets import fetch_openml
mnist = fetch_openml('mnist_784', version=1)
mnist.keys()
X, y = mnist["data"], mnist["target"]
import matplotlib as mpl
import matplotlib.pyplot as plt
some_digit = X[0] # **ERROR LINE** <---------
some_digit_image = some_digit.reshape(28, 28)
plt.imshow(some_digit_image, cmap = mpl.cm.binary, interpolation="nearest")
plt.axis("off")
plt.show()
我有这个错误：
---------------------------------------------------------------------------
KeyError Traceback (most recent call last)
~/.local/lib/python3.8/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
3079 try:
-> 3080 return self._engine.get_loc(casted_key)
3081 except KeyError as err:
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: 0
The above exception was the direct cause of the following exception:
KeyError Traceback (most recent call last)
<ipython-input-45-d5d685fca2de> in <module>
2 import matplotlib.pyplot as plt
3 import numpy as np
----> 4 some_digit = X[0]
5 some_digit_image = some_digit.reshape(28, 28)
6 plt.imshow(some_digit_image, cmap = mpl.cm.binary, interpolation="nearest")
~/.local/lib/python3.8/site-packages/pandas/core/frame.py in __getitem__(self, key)
3022 if self.columns.nlevels > 1:
3023 return self._getitem_multilevel(key)
-> 3024 indexer = self.columns.get_loc(key)
3025 if is_integer(indexer):
3026 indexer = [indexer]
~/.local/lib/python3.8/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
3080 return self._engine.get_loc(casted_key)
3081 except KeyError as err:
-> 3082 raise KeyError(key) from err
3083
3084 if tolerance is not None:
KeyError: 0
代码示例来自本书：Hands-on Machine Learning with Scikit-Learn, Keras, and TensorFlow
我试过 X.iloc[0] 但它也不起作用。
【问题讨论】：
-
您正在尝试访问名为
0的列。尝试打印出X.columns以了解可用的列，并打印X.index以查看可用的行 - 如果您想访问特定的行 + 列，请使用 -X.loc[row, col] -
请发布数据框样本
-
可以是字符串 '0' 而不是整数 0。试试 x['0']
-
['0'] 不起作用。 imgur.com/JwE57CQ