[FIXED] Sum values of a column for each value based on another column and divide it by total

Issue

Today I'm struggling once again with Python and data-analytics.

I got a dataframe which looks like this:

    name         totdmgdealt
0   Warwick      96980.0
1   Nami         25995.0
2   Draven       171568.0
3   Fiora        113721.0
4   Viktor       185302.0
5   Skarner      148791.0
6   Galio        130692.0
7   Ahri         145731.0
8   Jinx         182680.0
9   VelKoz       85785.0
10  Ziggs        46790.0
11  Cassiopeia   62444.0
12  Yasuo        117896.0
13  Warwick      129156.0
14  Evelynn      179252.0
15  Caitlyn      163342.0
16  Wukong       122919.0
17  Syndra       146754.0
18  Karma        35766.0
19  Warwick      117790.0
20  Draven       74879.0
21  Janna        11242.0
22  Lux          66424.0
23  Amumu        87826.0
24  Vayne        76085.0
25  Ahri         93334.0
..
..
..

this is a dataframe, which includes the total damage of a champion for one game. Now I want to group these information, so I can see which champion overall has the most damage dealt. I tried groupby('name') but it didn't work at all. I already went through some threads about groupby and summing values, but I didn't solve my specific problem.

The dealt damage of each champion should also be shown as percentage of the total.

I'm looking for something like this as an output:

    name     totdmgdealt  percentage
0   Warwick  2378798098     2.1  %
1   Nami     2837491074     2.3  %
2   Draven   1231451224     ..
3   Fiora    1287301724     ..
4   Viktor   1239808504     ..
5   Skarner  1487911234     ..
6   Galio    1306921234     ..

Solution

We can groupby on name and get the sum then we divide each value by the total with .div and multiply it by 100 with .mul and finally round it to one decimal with .round:

total = df['totdmgdealt'].sum()

summed = df.groupby('name', sort=False)['totdmgdealt'].sum().reset_index()

summed['percentage'] = summed.groupby('name', sort=False)['totdmgdealt']\
                             .sum()\
                             .div(total)\
                             .mul(100)\
                             .round(1).values

          name  totdmgdealt  percentage
0      Warwick     343926.0        12.2
1         Nami      25995.0         0.9
2       Draven     246447.0         8.7
3        Fiora     113721.0         4.0
4       Viktor     185302.0         6.6
5      Skarner     148791.0         5.3
6        Galio     130692.0         4.6
7         Ahri     239065.0         8.5
8         Jinx     182680.0         6.5
9       VelKoz      85785.0         3.0
10       Ziggs      46790.0         1.7
11  Cassiopeia      62444.0         2.2
12       Yasuo     117896.0         4.2
13     Evelynn     179252.0         6.4
14     Caitlyn     163342.0         5.8
15      Wukong     122919.0         4.4
16      Syndra     146754.0         5.2
17       Karma      35766.0         1.3
18       Janna      11242.0         0.4
19         Lux      66424.0         2.4
20       Amumu      87826.0         3.1
21       Vayne      76085.0         2.7

Answered By - Erfan