python-3.x - Python3 Pandas.DataFrame.info() 错误键 : 30

Question

所以我正在挖掘一些数据集，然后尝试使用 pandas 进行分析，然后我偶然发现了以下错误......我的大脑卡住了:(

这是引发异常的片段

import pandas as pd
from sklearn.datasets import load_breast_cancer


X, y = load_breast_cancer(return_X_y=True)
data = pd.DataFrame(X)
data['class'] = y
data.head()
data.tail()
data.columns
print('length of data is', len(data))
data.shape
data.info()

这是错误的引用

C:\Users\97150\PycharmProjects\EmbeddedLinux\venv\Scripts\python.exe C:/Users/97150/PycharmProjects/EmbeddedLinux/AI/project.py
length of data is 569
Traceback (most recent call last):
  File "C:\Users\97150\PycharmProjects\EmbeddedLinux\venv\lib\site-packages\pandas\core\indexes\base.py", line 2889, in get_loc
    return self._engine.get_loc(casted_key)
  File "pandas\_libs\index.pyx", line 70, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 97, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 1675, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas\_libs\hashtable_class_helper.pxi", line 1683, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 30

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:/Users/97150/PycharmProjects/EmbeddedLinux/AI/project.py", line 42, in <module>
    data.info()
  File "C:\Users\97150\PycharmProjects\EmbeddedLinux\venv\lib\site-packages\pandas\core\frame.py", line 2587, in info
    self, verbose, buf, max_cols, memory_usage, null_counts
  File "C:\Users\97150\PycharmProjects\EmbeddedLinux\venv\lib\site-packages\pandas\io\formats\info.py", line 250, in info
    self._verbose_repr(lines, ids, dtypes, show_counts)
  File "C:\Users\97150\PycharmProjects\EmbeddedLinux\venv\lib\site-packages\pandas\io\formats\info.py", line 335, in _verbose_repr
    dtype = dtypes[i]
  File "C:\Users\97150\PycharmProjects\EmbeddedLinux\venv\lib\site-packages\pandas\core\series.py", line 882, in __getitem__
    return self._get_value(key)
  File "C:\Users\97150\PycharmProjects\EmbeddedLinux\venv\lib\site-packages\pandas\core\series.py", line 991, in _get_value
    loc = self.index.get_loc(label)
  File "C:\Users\97150\PycharmProjects\EmbeddedLinux\venv\lib\site-packages\pandas\core\indexes\base.py", line 2891, in get_loc
    raise KeyError(key) from err
KeyError: 30

Process finished with exit code 1

注意:我使用的是 PyCharm 社区 2020.2，并检查了更新等，但没有任何变化

Answer 1

所以，事实证明， Pandas 的行为很奇怪。 从 data.info() 中删除 () 解决了这个问题:)