I have an if-else statement with over 100 "elses". Any ideas on how to condense this?-CodePudding

I'm guessing this question is going to get down voted but I could really use the help. I've coded a game in oTree for research purposes and the code below does exactly what I intend. The problem is that some games have over 100 rounds so you can see how the code could get ridiculously long. For people who are going to use this code in the future, it is practically unreadable in its current form. Any ideas on how I could condense this into a simpler if statement?

If you are unfamiliar with oTree, the "participant" signifier is essentially a way to pass data across rounds. The "player" reflects the participant specific to a round number. So each round I need to save their current round return (player.r#) and call the returns of all past rounds (participant.r#-1).

if subsession.round_number == 1:
    participant = player.participant
    participant.r1 = round(100 * asset, 3)   100
    player.r1 = participant.r1
elif subsession.round_number == 2:
    participant = player.participant
    participant.r2 = round(participant.r1 * asset, 3)   participant.r1
    player.r1 = participant.r1
    player.r2 = participant.r2
elif subsession.round_number == 3:
    participant = player.participant
    participant.r3 = round(participant.r2 * asset, 3)   participant.r2
    player.r1 = participant.r1
    player.r2 = participant.r2
    player.r3 = participant.r3
elif subsession.round_number == 4:
    participant = player.participant
    participant.r4 = round(participant.r3 * asset, 3)   participant.r3
    player.r1 = participant.r1
    player.r2 = participant.r2
    player.r3 = participant.r3
    player.r4 = participant.r4
elif subsession.round_number == 5:
    participant = player.participant
    participant.r5 = round(participant.r4 * asset, 3)   participant.r4
    player.r1 = participant.r1
    player.r2 = participant.r2
    player.r3 = participant.r3
    player.r4 = participant.r4
    player.r5 = participant.r5

CodePudding user response：

You can use getattr and setattr for this and avoid ifs at all.
getattr(self, name) # equal to: self.name
setattr(self, name, value) # equal to: self.name = value

The final code would be something like:

r_n = subsession.round_number
participant = player.participant

setattr(participant, 'r'   str(r_n), round(getattr(participant, 'r'   str(r_n - 1)) * asset, 3)   getattr(participant, 'r'   str(r_n - 1))

for i in range(1, r_n 1):
    player_id = 'r'   str(i) 
    setattr(player, player_id, getattr(participant, 'r'   str(player_id)))

UPD: Don't forget to add condition for r1. Suddenly there will be if that we tried to avoid :D

CodePudding user response：

I’m know that dictionaries are often used switch statements so that’s some to look into. If you don’t know what switch statements are; they’re similar to if statements that they’re conditional blocks of code. But instead of checking a Boolean they check if a certain variable is a certain case. Python doesn’t have switch statements but dictionaries can be used as a replacement.