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当特定列包含向我发出信号应删除该行的值时,如何删除Pandas数据框中的行?

[英]How do I delete a row in Pandas dataframe when a specific column contains a value that signals to me that the row should be deleted?

Very simple question everyone, but nearly impossible to find answers to basic questions in official documentation. 每个人都非常简单的问题,但是几乎不可能在官方文档中找到基本问题的答案。

I have a dataframe object in Pandas that has rows and columns. 我在Pandas中有一个具有行和列的dataframe对象。

One of the columns, named "CBSM", contains boolean values. 名为“ CBSM”的列之一包含布尔值。 I need to delete all rows from the dataframe where the value of the CBSM column = "Y". 我需要从数据框CBSM列的值=“ Y”删除所有行。

I see that there is a method called dataframe.drop() 我看到有一个名为dataframe.drop()的方法

Label, Axis, and Level are 3 parameters that the drop() method takes in. I have no clue what values to provide these parameters to accomplish my need of deleting the rows in the fashion I described above. Label,Axis和Level是drop()方法采用的3个参数。我不知道提供这些参数的值是什么,以上述方式完成删除行的需求。 I have a feeling the drop() method is not the right way to do what I want. 我感觉drop()方法不是执行我想要的正确方法。

Please advise, thanks. 请指教,谢谢。

This method is called boolean indexing . 此方法称为布尔索引

You can try loc with str.contains : 您可以尝试locstr.contains

df.loc[~df['CBSM'].str.contains('Y')] 

Sample: 样品:

print df
   A CBSM  L
0  1    Y  4
1  1    N  6
2  2    N  3

print df['CBSM'].str.contains('Y')
0     True
1    False
2    False
Name: CBSM, dtype: bool

#inverted boolean serie
print ~df['CBSM'].str.contains('Y')
0    False
1     True
2     True
Name: CBSM, dtype: bool

print df.loc[~df['CBSM'].str.contains('Y')] 
   A CBSM  L
1  1    N  6
2  2    N  3

Or: 要么:

print df.loc[~(df['CBSM'] == 'Y')] 
   A CBSM  L
1  1    N  6
2  2    N  3

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