import numpy as np

repeatCheck = 3 # # How many repeats are not *allowed*
column = 3 # Which column should be checked for repeats
src = 'stimlist.csv' # A tab separated text file in the file pool

# Load the conditions into a NumPy array
a = np.loadtxt(exp.get_file(src), delimiter='\t', dtype=str)

# Go into a 'shuffle loop'
while True:
    # Shuffle the array
    np.random.shuffle(a)

    # Loop from trial 0 to (number-of-trials - repeatCheck).
    shuffleAgain = False
    for i in range(len(a)-repeatCheck):
        # Get a slice out of the condition matrix that goes from i to
        # i+repeatCheck, including only the specified column
        slice = a[i:i+repeatCheck, column]
        # If the length of the list of unique items in that slice is 1
        # (i.e. if they are all the same), we need to shuffle the
        # list again
        if len(np.unique(slice)) == 1:
            shuffleAgain = True
    # If we don't need to shuffle again, exit the 'shuffle loop'
    if not shuffleAgain:
        break
# Store the array as exp.stimlist, so we can access it later on
exp.stimlist = a