Pandas：按多列中的值过滤(Pandas: Filter by values within multiple columns)

 我正在尝试根据单个条件中的多个列中的值过滤数据帧，但保留其他列，我根本不想应用过滤器。 
 
 我已经回顾了这些答案，第三个是最接近的，但仍然没有运气： 
 
 
 
 如何按多列过滤pandas数据帧 
 
 
 过滤多列Pandas 
 
 
 Python Pandas - 如何按一个值过滤多个列 
 
 
 建立： 
 
import pandas as pd

df = pd.DataFrame({
        'month':[1,1,1,2,2],
        'a':['A','A','A','A','NONE'],
        'b':['B','B','B','B','B'],
        'c':['C','C','C','NONE','NONE']
    }, columns = ['month','a','b','c'])

l = ['month','a','c']
df = df.loc[df['month'] == df['month'].max(), df.columns.isin(l)].reset_index(drop = True)
 
 电流输出： 
 
   month     a     c
0      2     A  NONE
1      2  NONE  NONE
 
 期望的输出： 
 
   month     a
0      2     A
1      2  NONE
 
 我试过了： 
 
sub = l[1:]
df = df[(df.loc[:, sub] != 'NONE').any(axis = 1)]
 
 和许多其他变化（ .all() ， [sub, :] ， ~df.loc[...] ， (axis = 0) ），但都没有运气。 
 
 基本上我想删除其中包含所有“NONE”值的任何列（在sub列表中）。 
 
 任何帮助深表感谢。 

I'm trying to filter a dataframe based on the values within the multiple columns, based on a single condition, but keep other columns to which I don't want to apply the filter at all. 
 
I've reviewed these answers, with the third being the closest, but still no luck:
 
 
 
how do you filter pandas dataframes by multiple columns
 
 
Filtering multiple columns Pandas
 
 
Python Pandas - How to filter multiple columns by one value
 
 
Setup:
 
import pandas as pd

df = pd.DataFrame({
        'month':[1,1,1,2,2],
        'a':['A','A','A','A','NONE'],
        'b':['B','B','B','B','B'],
        'c':['C','C','C','NONE','NONE']
    }, columns = ['month','a','b','c'])

l = ['month','a','c']
df = df.loc[df['month'] == df['month'].max(), df.columns.isin(l)].reset_index(drop = True)
 
Current Output:
 
   month     a     c
0      2     A  NONE
1      2  NONE  NONE
 
Desired Output:
 
   month     a
0      2     A
1      2  NONE
 
I've tried:
 
sub = l[1:]
df = df[(df.loc[:, sub] != 'NONE').any(axis = 1)]
 
and many other variations (.all(), [sub, :], ~df.loc[...], (axis = 0)), but all with no luck.
 
Basically I want to drop any column (within the sub list) that has all 'NONE' values in it.
 
Any help is much appreciated.

原文：https://stackoverflow.com/questions/44416069