Hi I am new and learning pandas for data analysis. I have 2 columns data
A B
1 2
2 3
3 4
4 5
I want to create a third column C which result would be calculated by column B , by subtracting upper value with current one and dividing by current.
A B C
1 2
2 3 0.33
3 4 0.25
4 5 0.2
for example first row value for C column is empty because there is no value above 2 .
0.33 = > 3 - 2 / 3 ,
0.25 = > 4 - 3 / 4 ,
0.2 = > 5 - 4 / 5 and so on
I am stuck while getting the upper value of current column. Need help how to achieve that.