Create list from pandas dataframe - list

Question

I have a function that takes all, non-distinct, MatchId and (xG_Team1 vs xG_Team2, paired) and gives an output of as an array. which then summed up to be sse constant.
The problem with the function is it iterates through each row, duplicating MatchId. I want to stop this.
For each distinct MatchId I need the corresponding home and away goals as a list. I.e. Home_Goal and Away_Goal to be used in each iteration. from Home_Goal_time and Away_Goal_time columns of the dataframe. The list below doesn't seem to work.
MatchId Event_Id EventCode Team1 Team2 Team1_Goals
0 842079 2053 Goal Away Huachipato Cobresal 0
1 842079 2053 Goal Away Huachipato Cobresal 0
2 842080 1029 Goal Home Slovan lava 3
3 842080 1029 Goal Home Slovan lava 3
4 842080 2053 Goal Away Slovan lava 3
5 842080 1029 Goal Home Slovan lava 3
6 842634 2053 Goal Away Rosario Boca Juniors 0
7 842634 2053 Goal Away Rosario Boca Juniors 0
8 842634 2053 Goal Away Rosario Boca Juniors 0
9 842634 2054 Cancel Goal Away Rosario Boca Juniors 0
Team2_Goals xG_Team1 xG_Team2 CurrentPlaytime Home_Goal_Time Away_Goal_Time
0 2 1.79907 1.19893 2616183 0 87
1 2 1.79907 1.19893 3436780 0 115
2 1 1.70662 1.1995 3630545 121 0
3 1 1.70662 1.1995 4769519 159 0
4 1 1.70662 1.1995 5057143 0 169
5 1 1.70662 1.1995 5236213 175 0
6 2 0.82058 1.3465 2102264 0 70
7 2 0.82058 1.3465 4255871 0 142
8 2 0.82058 1.3465 5266652 0 176
9 2 0.82058 1.3465 5273611 0 0
For example MatchId = 842079, Home_goal =[], Away_Goal = [87, 115]
x1 = [1,0,0]
x2 = [0,1,0]
x3 = [0,0,1]
m = 1 ,arbitrary constant used to optimise sse.
k = 196
total_timeslot = 196
Home_Goal = [] # No Goal
Away_Goal = [] # No Goal
def sum_squared_diff(x1, x2, x3, y):
ssd = []
for k in range(total_timeslot): # k will take multiple values
if k in Home_Goal:
ssd.append(sum((x2 - y) ** 2))
elif k in Away_Goal:
ssd.append(sum((x3 - y) ** 2))
else:
ssd.append(sum((x1 - y) ** 2))
return ssd
def my_function(row):
xG_Team1 = row.xG_Team1
xG_Team2 = row.xG_Team2
return np.array([1-(xG_Team1*m + xG_Team2*m)/k, xG_Team1*m/k, xG_Team2*m/k])
results = df.apply(lambda row: sum_squared_diff(x1, x2, x3, my_function(row)), axis=1)
results
sum(results.sum())
For the three matches above the desire outcome should look like the following.
If I need an individual sse, sum(sum_squared_diff(x1, x2, x3, y)) gives me the following.
MatchId = 842079 = 3.984053038520635
MatchId = 842080 = 7.882189570700502
MatchId = 842080 = 5.929085973050213
Given the size of the original data, realistically I am after the total sum of the sse. For the above sample data, simply adding up the values give total sse=17.79532858227135.` Once I achieve this, then I will try to optimise the sse based on this figure by updating the arbitrary value m.
Here are the lists i hoped the function will iterate over.
Home_scored = s.groupby('MatchId')['Home_Goal_time'].apply(list)
Away_scored = s.groupby('MatchId')['Away_Goal_Time'].apply(list)
type(HomeGoal)
pandas.core.series.Series
Then convert it to lists.
Home_Goal = Home_scored.tolist()
Away_Goal = Away_scored.tolist()
type(Home_Goal)
list
Home_Goal
Out[303]: [[0, 0], [121, 159, 0, 175], [0, 0, 0, 0]]
Away_Goal
Out[304]: [[87, 115], [0, 0, 169, 0], [70, 142, 176, 0]]
But the function still takes Home_Goal and Away_Goal as empty list.

Answer 1

If you only want to consider one MatchId at a time you should .groupby('MatchID') first
df.groupby('MatchID').apply(...)