CODEWITHSUNDEEP
pythonpandasdataframe
Vincent Clerc
Vincent Clerc

Reputation: 103

regrouping similar column values in pandas

I have dataframe with many lines and columns, looking like this :

index col1 col2
1 0 1
2 5 1
3 5 4
4 5 4
5 3 4
6 2 4
7 2 1
8 2 2

I would like to keep only the values that are different from the previous index and replace the others by 0. On the example dataframe, it would be :

index col1 col2
1 0 1
2 5 0
3 0 4
4 0 0
5 3 0
6 2 0
7 0 1
8 0 2

What is a solution that works for any number of row/columns ?

Upvotes: 0

Views: 56

Answers (1)

Mustafa Aydın
Mustafa Aydın

Reputation: 18315

So you'd like to keep the values where the difference to previous row is not equal to 0 (i.e., they're not the same), and put 0 to other places:

>>> df.where(df.diff().ne(0), other=0)
       col1  col2
index
1         0     1
2         5     0
3         0     4
4         0     0
5         3     0
6         2     0
7         0     1
8         0     2

Upvotes: 2

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