CODEWITHSUNDEEP
pythonpandasdataframe
William
William

Reputation: 4028

pandas how to check if the following 2 rows have the same column value

I have a df:

df = pd.DataFrame([[1,2], [9,0],[3,4], [3,4]], columns=list('AB'))

output:

    A   B
0   1   2
1   9   0
2   3   4
3   3   4

The length of the df is always even. I need to divide the rows by 2 ,it means ,first row compare with second row ,third row compare with forth row ,...,n-1 row compare with n row. My question is how to check if the column values of each 2 rows is exact the same.

For example, the first row and the second row are not the same ,but the third row and forth row are the same.

Upvotes: 2

Views: 638

Answers (2)

mozway
mozway

Reputation: 260640

Do you want:

df.iloc[::2].eq(df.iloc[1::2].values)

Output:

       A      B
0  False  False   # first row (index=0) vs second (index=1)
2   True   True   # third row (index=2) vs fourth (index=3)

To test equality of all columns:

df.iloc[::2].eq(df.iloc[1::2].values).all(axis=1)

Output:

0    False
2     True
dtype: bool

Upvotes: 1

Simon Ward-Jones
Simon Ward-Jones

Reputation: 126

df['pairs'] = df.index // 2
(df.groupby('pairs').apply('nunique') == 1).apply(all, axis=1)

Upvotes: 0

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