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pythonpandas

extract rows with change in consecutive values of a column from pandas dataframe

I am trying to extract the rows where consecutive value changes for a particular column

Ex:

sno A   B
1   a   yes
2   b   yes
3   c   No
4   d   No
5   e   No
6   f   yes
7   g   yes
8   h   yes
9   I   No

Output:

sno A   B
        
2   b   yes
3   c   No
5   e   No
6   f   yes     
8   h   yes
9   I   No

Consecutive column is B, am trying to extract if the value of column B is changed consecutively

Solution

  • Another possible solution:

    d = df['B'].shift().ne(df['B']) 
e = ~d & d.shift(-1)
df[e | e.shift()]

    Intermediates:

    d:

    0     True
1    False
2     True
3    False
4    False
5     True
6    False
7    False
8     True
Name: B, dtype: bool

    e:

    0    False
1     True
2    False
3    False
4     True
5    False
6    False
7     True
8    False
Name: B, dtype: bool

    Output:

       sno  A    B
1    2  b  yes
2    3  c   No
4    5  e   No
5    6  f  yes
7    8  h  yes
8    9  I   No