Referencing string names in df to outside variables

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Referencing string names in df to outside variables - illmattic - Nov-16-2021

I am trying to create a point system of NFL teams calculating points based on wins and losses relating to how many points they win by and the strength of their opponent.

I have the following df:

Output:Date	           Visitor	           Home           Visitor Score	 Home Score
11/14/2021	Minnesota Vikings	Los Angeles Chargers	27	20
11/14/2021	Philadelphia Eagles	Denver Broncos	        30	13
11/14/2021	Seattle Seahawks	Green Bay Packers	0	17
11/14/2021	Kansas City Chiefs	Las Vegas Raiders	41	14
11/15/2021	Los Angeles Rams	San Francisco 49ers	10	31

my current thinking about how to calculate the points according to how many points they win by is the following:

gb = 0

for game in range(len(nfl_df)):
    if nfl_df['Visitor'][game] == 'Green Bay Packers' and nfl_df['Visitor Score'][game] - nfl_df['Home Score'][game] < 9 and nfl_df['Visitor Score'][game] - nfl_df['Home Score'][game] > 0:
        gb += 3
    elif nfl_df['Visitor'][game] == 'Green Bay Packers' and nfl_df['Visitor Score'][game] - nfl_df['Home Score'][game] < 17 and nfl_df['Visitor Score'][game] - nfl_df['Home Score'][game] > 8:
        gb += 5
    elif nfl_df['Visitor'][game] == 'Green Bay Packers' and nfl_df['Visitor Score'][game] - nfl_df['Home Score'][game] > 16:
        gb += 7   
    else:
        pass

but if I were to do this with each team it would be a lot of code and I'm sure there is a simpler way to do it. But also, I don't know how to incorporate the strength of the opponent because variable 'gb' has no connection to the string value 'Green Bay Packers' which appears in the df. After each week I would like to have a team's points updated based on their win/loss for that week and incorporate that number into the win/loss calculation. For example, if Green Bay beats Dallas (a team with 50 points) I would have the points from the victory multiply by the total points the opponent has (3*50). I'm just stuck on how to reference the teams' names in the df ('Green Bay Packers', 'Dallas Cowboys') to their point variables (gb, dal)

Any help would be appreciated
Matt

RE: Referencing string names in df to outside variables - jefsummers - Nov-16-2021

You almost never want to loop through a dataframe. A lot of the point of dataframes is the ability to do things as a vector.
So, not using a loop (this is untested as I don't have your dataframe)

nfl_df['Home Wins'] = (nfl_df['Home Score'] > nfl_df['Visitor Score'])
nfl_df['Margin'] = abs(nfl_df['Home Score'] - nfl_df['Visitor Score'])

I would also just extract a set of the team names. Using a set eliminates duplicates