Find highest growth using python pandas?

Question

I have a dataframe named growth with 4 columns.

State Name  Average Fare ($)_x  Average Fare ($)_y  Average Fare ($)
0   AK  599.372368  577.790640  585.944324
1   AL  548.825867  545.144447  555.939466
2   AR  496.033146  511.867026  513.761296
3   AZ  324.641818  396.895324  389.545267
4   CA  368.937971  376.723839  366.918761
5   CO  502.611572  537.206439  531.191893
6   CT  394.105453  388.772428  370.904182
7   DC  390.872738  382.326510  392.394165
8   FL  324.941100  329.728524  337.249248
9   GA  485.335737  480.606365  489.574241
10  HI  326.084793  335.547369  298.709998
11  IA  428.151682  445.625840  462.614195
12  ID  482.092567  475.822275  491.714945
13  IL  329.449503  349.938794  346.022226
14  IN  391.627917  418.945137  412.242053
15  KS  452.312058  490.024059  420.182836

The last three columns are the average fare of each year of each state. 2nd,3rd,4th column being year 2017,2018,2019 respectively. I wanted to find out that which state has highest growth in fare since 2017.

I tried with this code of mine and it gives some output that I cant really understand. I just need to find the state that has highest fare growth since 2017.

my code:

growth[['Average Fare ($)_x','Average Fare ($)_y','Average Fare ($)']].pct_change()

Answer 1

You can you this

df.set_index('State_name').pct_change(periods  = 1, axis='columns').idxmax()

Change the periods value to 2 if you want to calculate the difference between first year & the 3rd year.

output

Average_fare_x    NaN
Average_fare_y     AZ #state with max change between 1st & 2nd year
Average_fare       WV #state with max change between 2nd & 3rd year