CODEWITHSUNDEEP
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AmirX
AmirX

Reputation: 2717

finding the difference of sum in percentage after groupby in pandas

I have a dataframe like this:

df = pd.DataFrame({'x': ['a', 'a', 'a', 'a', 'b', 'b', 'b', 'b'], 'y': [0,1,0,1,0,1,0,1], 'z':[100, 102, 110, 115, 200, 202, 230, 240]})

   x  y    z
0  a  0  100
1  a  1  102
2  a  0  110
3  a  1  115
4  b  0  200
5  b  1  202
6  b  0  230
7  b  1  240

After this:

df.groupby(['x', 'y'])['z'].sum()

x  y
a  0    210
   1    217
b  0    430
   1    442

I want to find out the difference between sums in percentage for each group. In other words I want this:

(217-210)/210 = 3.33
(442-430)/430 = 2.79

Upvotes: 2

Views: 238

Answers (1)

yatu
yatu

Reputation: 88236

You could groupby both x and y and take the sum as you already do, and then use DataFrame.pct_change to take the percentage change having grouped again by x:

g = df.groupby(['x','y'])['z'].sum()
g.groupby(level=0).pct_change().mul(100).dropna().reset_index(drop=True, level=1)

x
a    3.333333
b    2.790698
Name: z, dtype: float64

Upvotes: 1

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