GROUPBY with showing all the columns
Did you try this : d_copy.groupby(['CITYS','MODELS']).mean() to have the average percentage of a model by city.
Then if you want to catch the percentages you have to convert it in DF and select the column : pd.DataFrame(d_copy.groupby(['CITYS','MODELS']).mean())['PERCENTAGE']
I want to do a groupby of my MODELS by CITYS with keeping all the columns where i can print the percentage of each MODELS IN THIS CITY. 
I put my dataframe in PHOTO below.
And i have written this code but i don"t know how to do ??
for name,group in d_copy.groupby(['CITYS'])['MODELS']: