Create white noise stimulus in python using psychopy

white_noise.py

# Generate noise frames
# dependencies: psychopy, python-numpy, python-pyglet
from numpy import random 
from psychopy import visual

# create a window
win = visual.Window([800, 600], monitor="testMonitor", units="deg")

maskDuration = 180 # Duration of mask in frames
visualNoiseSize = 512 # Dimension in pixels of visual noise. Must be a power of 2
noiseSize = 512
visualNoise = []  # list of rendered frames
for n in range(maskDuration):
    noiseTexture = random.rand(visualNoiseSize,visualNoiseSize)*2-1
    visualNoise += [visual.PatchStim(win=win, tex=noiseTexture, size=(visualNoiseSize,visualNoiseSize), units='pix',interpolate=False, mask='gauss')]
    visualNoise[-1].draw()  # first draw is slower. So do it now.

win.clearBuffer()

# ACTION: shows mask and the trial's stimulus
for frame in range(maskDuration):
    visualNoise[frame].draw()
    stim.draw()