CODEWITHSUNDEEP
pythonpython-3.xpandasdataframe
Hamza Waheed
Hamza Waheed

Reputation: 155

How can I use values in an old dataframe to calculate a new dataframe?

So I have a dataframe with certain values and I want to create a new dataframe with percentage differences from the old dataframe.

My existing dataframe is something like this:

Years          A              B          C           D          E
2020        801.566522  769.2986786 830.8725406 830.8725406 840.7192069
2021-2030   786.3122361 759.3832642 826.2453567 826.2453567 838.7446964
2031-2050   787.6490105 759.1486884 827.4489946 827.4489946 839.8352851
2041-2050   775.1016567 745.1193567 817.2389842 817.2389842 831.9880991

The new dataframe should calculate the percentage difference between the 2020 values and the values between subsequent decades, and should look something like this.

Years           A                 B               C                D            E
2021-2030   -0.019030593    -0.012888901    -0.005569066    -0.005569066    -0.002348597
2031-2050   -0.01736289     -0.013193823    -0.004120423    -0.004120423    -0.001051388
2041-2050   -0.03301643     -0.031430344    -0.016408722    -0.016408722    -0.010385284

I can do this in excel quite easily but since I have a large number of these files, I wanted to do it in python instead. Can anyone help me out with a basic solution for this?

Upvotes: 0

Views: 35

Answers (1)

mightyandweakcoder
mightyandweakcoder

Reputation: 846

Just do

df=yourdataframe.pct_change()

The first row of the dataframe will be of NaN values and if you'd like to keep it in the format you'd shown just

yourdataframe=df.iloc[1:]

This will remove the first row of the dataframe

Upvotes: 1

Related Questions