Pandas - cumulative sum of two columns

[Yoriz]

I think you might have your desired output cumulative sums mixed up(or i don't understand), this output is not the same but i think it could be what you are after.

import pandas as pd

df = pd.DataFrame([
    ["Gothenburg", "Malmo", 2018, 1, 1],
    ["Malmo", "Gothenburg",  2018, 1, 1],
    ["Malmo", "Gothenburg", 2018, 0, 3],
    ["Gothenburg", "Malmo", 2018, 1, 1],
    ["Gothenburg", "Malmo", 2018, 0, 3],
    ["Gothenburg", "Malmo", 2018, 1, 1],
    ["Gothenburg", "Malmo", 2018, 0, 3],
    ["Malmo", "Gothenburg", 2018, 0, 3],
    ["Gothenburg", "Malmo", 2018, 1, 1],
    ["Malmo", "Gothenburg", 2018, 0, 3],
    ["Malmo", "Gothenburg", 2018, 1, 1],
    ["Malmo", "Gothenburg", 2018, 0, 3],
])

df.columns = ['H_team', 'A_team', 'Year', 'H_points', 'A_points']
df['H_cumsum'] = df['H_points'].cumsum().shift(1)
df['A_cumsum'] = df['A_points'].cumsum().shift(1)
print(df)

Output:
        H_team      A_team  Year  H_points  A_points  H_cumsum  A_cumsum
0   Gothenburg       Malmo  2018         1         1       NaN       NaN
1        Malmo  Gothenburg  2018         1         1       1.0       1.0
2        Malmo  Gothenburg  2018         0         3       2.0       2.0
3   Gothenburg       Malmo  2018         1         1       2.0       5.0
4   Gothenburg       Malmo  2018         0         3       3.0       6.0
5   Gothenburg       Malmo  2018         1         1       3.0       9.0
6   Gothenburg       Malmo  2018         0         3       4.0      10.0
7        Malmo  Gothenburg  2018         0         3       4.0      13.0
8   Gothenburg       Malmo  2018         1         1       4.0      16.0
9        Malmo  Gothenburg  2018         0         3       5.0      17.0
10       Malmo  Gothenburg  2018         1         1       5.0      20.0
11       Malmo  Gothenburg  2018         0         3       6.0      21.0