Hello,
I want to assign one control group and 3 treatment groups in my survey. I used this code but when I run the demo with 4 participants all of them are assigned to the control group.
Can someone help me?


class Subsession(BaseSubsession):
    def creating_session(self):
        num_participants = len(self.get_players())
        num_treatment_groups = 3

        # Calculate the number of participants per treatment group
        participants_per_group = num_participants // (num_treatment_groups + 1)
        remaining_participants = num_participants % (num_treatment_groups + 1)

        # Assign participants to the control group
        control_group = self.get_players()[:participants_per_group]

        # Assign remaining participants to the treatment groups
        treatment_groups = [self.get_players()[i:i + participants_per_group] for i in range(participants_per_group, num_participants, participants_per_group)]

        # Set group matrix
        self.set_group_matrix([control_group] + treatment_groups)

        # Print for debugging
        print("Control Group:")
        for player in control_group:
            print(f"Participant {player.participant.label} treatment group: {player.treatment_group}")

        print("Treatment Groups:")
        for i, group in enumerate(self.get_groups()):
            for player in group.get_players():
                print(f"Participant {player.participant.label} treatment group: {player.treatment_group}")