【发布时间】：2018-03-26 21:48:36
【问题描述】：
所以我只是在学习 pandas 库，我认为这应该没有那么难，而且我不知道为什么我会被抛出一个 Key Error。我可能做错了，因为我是 python 的初学者。但我想知道为什么我无法使用以下代码找到 csv 的中位数？我也在使用 repl.it 来运行这段代码。
import pandas
census = pandas.read_csv("census(1).csv")
median = census[0].median()
print(median)
如果您需要，我可以发布 csv，如果这可能有助于调试。我正在尝试获取第一列的中位数，我会按名称调用它，但该列没有标题。我查看了我的书，如果列没有标题，他们如何指示它被编码。抛出的关键错误是
Traceback (most recent call last):
File "/tmp/.site-packages/pandas/core/indexes/base.py", line 2525, in get_loc
return self._engine.get_loc(key)
File "pandas/_libs/index.pyx", line 117, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/hashtable_class_helper.pxi", line 1265, in pandas._libs.hashtable.PyObjectHashTable.get_item
File "pandas/_libs/hashtable_class_helper.pxi", line 1273, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 0
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "main.py", line 5, in <module>
median = census[0].median()
File "/tmp/.site-packages/pandas/core/frame.py", line 2139, in __getitem__
return self._getitem_column(key)
File "/tmp/.site-packages/pandas/core/frame.py", line 2146, in _getitem_column
return self._get_item_cache(key)
File "/tmp/.site-packages/pandas/core/generic.py", line 1842, in _get_item_cache
values = self._data.get(item)
File "/tmp/.site-packages/pandas/core/internals.py", line 3843, in get
loc = self.items.get_loc(item)
File "/tmp/.site-packages/pandas/core/indexes/base.py", line 2527, in get_loc
return self._engine.get_loc(self._maybe_cast_indexer(key))
File "pandas/_libs/index.pyx", line 117, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/hashtable_class_helper.pxi", line 1265, in pandas._libs.hashtable.PyObjectHashTable.get_item
File "pandas/_libs/hashtable_class_helper.pxi", line 1273, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 0
csv 的前两行：
39 State-gov 77516 Bachelors 13 Never-married Adm-clerical Not-in-family White Male 2174 0 40 United-States <=50K
50 Self-emp-not-inc 83311 Bachelors 13 Married-civ-spouse Exec-managerial Husband White Male 0 0 13 United-States <=50K
【问题讨论】：
-
显然没有名为
0的列。最好为我们提供 2 行 csv 并在您读入后显示数据框census。 -
这里是 csv 的前两行 39 State-gov 77516 单身汉 13 未婚的 Adm-clerical 非家庭白人男性 2174 0 40 美国
-
除非我的答案是您需要的，否则您还需要包含列名。