filtering columns with same values in a dataframe - Python

Question

I am trying to filter all the columns in a dataframe for the same value:

This is my dataframe:

df=pd.DataFrame({'A':['valid','invalid','valid'],'B':['valid','valid','valid'],'C':['valid','invalid','invalid']})

I want the just the records which has only value 'valid'

What i tried was:

udf=(lambda x: x=='valid')
df1=df.applymap(udf)
df1

       A     B      C
0   True  True   True
1  False  True  False
2   True  True  False

again i dont know have to filter the records that has True alone. how do i do it?

Actual df output
         A      B        C
0    valid  valid    valid
1  invalid  valid  invalid
2    valid  valid  invalid

Expected ouput
       A     B      C
0   valid  valid    valid

can someone help me?

jezrael · Accepted Answer · 2019-03-25 08:57:22Z

3

Compare all values by DataFrame.eq and get rows with all values Trues by DataFrame.all:

df1 = df[df.eq('valid').all(axis=1)]
#same like
#df1 = df[(df == 'valid').all(axis=1)]
print (df1) 
       A      B      C
0  valid  valid  valid

Details:

print (df.eq('valid')) 
       A     B      C
0   True  True   True
1  False  True  False
2   True  True  False

print (df.eq('valid').all(axis=1))
0     True
1    False
2    False
dtype: bool

answered Mar 25, 2019 at 8:57

jezrael

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