Shuffle playlists for SRC-HRC randomization without repeating SRCs

shuffle-playlist.py

import random
from pprint import pprint

sources = 2
conditions = 2
subjects = 3
playlists = {}

for subject in range(1, subjects + 1):

    playlist     = []
    it           = 1

    all_pvs_conditions = list(xrange(1, conditions + 1)) * sources

    while True:
        # end if no more are available
        if len(playlist) == sources * conditions:
            break

        src_list_shuffled = list(xrange(1, sources + 1))
        while len(src_list_shuffled):
            next_src       = random.choice(src_list_shuffled)
            next_condition = random.choice(all_pvs_conditions)

            if [next_src, next_condition] not in playlist:
                src_list_shuffled.remove(next_src)
                all_pvs_conditions.remove(next_condition)
                playlist.append([next_src, next_condition])

    playlists[subject] = playlist

pprint(playlists)