Randomize conditions with even frequency for experiment

I'm referencing a list of three conditions for an experiment:

conditions = [1, 2, 3]

I need to randomize the condition each time the program is run, which is easy:

condition = random.choice(conditions)

My problem is that the program starts fresh each time for each participant, but I need an even amount of participants from each condition (i.e., if there are six participants, then I need two to have been assigned to each condition), so simply randomizing doesn't work, and I cannot create a loop to reference the conditions used because it starts from scratch each time. Any way I can randomize a selection from the list, but keep an even frequency for each possible selection?