Python Pandas：Dataframe.Drop - ValueError：标签 ['id'] 未包含在轴中
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Pandas: Dataframe.Drop - ValueError: labels ['id'] not contained in axis
提问by saar
Attempting to drop a column from a DataFramein Pandas. DataFramecreated from a text file.
试图从DataFramePandas 中的a中删除一列。 DataFrame从文本文件创建。
import pandas as pd
df = pd.read_csv('sample.txt')
df.drop(['a'], 1, inplace=True)
However, this generates the following error:
但是，这会产生以下错误：
ValueError: labels ['a'] not contained in axis
Here is a copy of the sample.txtfile :
这是sample.txt文件的副本：
a,b,c,d,e
1,2,3,4,5
2,3,4,5,6
3,4,5,6,7
4,5,6,7,8
Thanks in advance.
提前致谢。
回答by Rob Davis
So the issue is that your "sample.txt" file doesn't actually include the data you are trying to remove.
所以问题是您的“sample.txt”文件实际上并不包含您要删除的数据。
Your line
你的线路
df.drop(['id'], 1, inplace=True)
is attepmting to take your DataFrame (which includes the data from your sample file), find the column where the value is 'id' in the first row (axis 1) and do an inplace replace (modify the existing object rather than create a new object missing that column, this will return None and just modify the existing object.).
正在尝试获取您的 DataFrame（其中包括您的示例文件中的数据），在第一行（轴 1）中找到值为“id”的列并进行就地替换（修改现有对象而不是创建一个新对象）对象缺少该列，这将返回 None 并只修改现有对象。）。
The issue is that your sample data doesn't include a column with a header equal to 'id'.
问题是您的示例数据不包含标题等于“id”的列。
In your current sample file, you can only to a drop where the value in axis 1 is 'a', 'b', 'c', 'd', or 'e'. Either correct your code to drop one of those values or get a sample files with the correct header.
在您当前的示例文件中，您只能删除轴 1 中的值为“a”、“b”、“c”、“d”或“e”的放置。要么更正您的代码以删除这些值之一，要么获取带有正确标题的示例文件。
The documentation for Pandas isn't fantastic, but here is a good example of how to do a column drop in Pandas: http://chrisalbon.com/python/pandas_dropping_column_and_rows.html
Pandas 的文档不是很好，但这里是如何在 Pandas 中进行列删除的一个很好的例子：http: //chrisalbon.com/python/pandas_dropping_column_and_rows.html
** Below added in response to Answer Comment from @saar
** 以下添加以回应@saar 的回答评论
Here is my example code: Sample.txt:
这是我的示例代码：Sample.txt：
a,b,c,d,e
1,2,3,4,5
2,3,4,5,6
3,4,5,6,7
4,5,6,7,8
Sample Code:
示例代码：
import pandas as pd
df = pd.read_csv('sample.txt')
print('Current DataFrame:')
print(df)
df.drop(['a'], 1, inplace=True)
print('\nModified DataFrame:')
print(df)
Output:
输出：
>>python panda_test.py
Current DataFrame:
a b c d e
0 1 2 3 4 5
1 2 3 4 5 6
2 3 4 5 6 7
3 4 5 6 7 8
Modified DataFrame:
b c d e
0 2 3 4 5
1 3 4 5 6
2 4 5 6 7
3 5 6 7 8
回答by user8423842
bad= pd.read_csv('bad_modified.csv')
A=bad.sample(n=10)
B=bad.drop(A.index,axis=0)
This is an example of dropping a dataframe partly. In case you need it.
这是部分丢弃数据帧的示例。万一你需要它。
