Create Two sequential tasks for images in Vizard

[turinlife]

I'm new in Vizard. I'm trying to create a simple code to perform two tasks sequentially for a specific time set:

A black image for 0.8 seconds
A sequence of images (from a folder) taken randomly, for 1.5 seconds. I can perform these task separately, but I can't merge together. Suggestions are very appreciated, thank you

import viz
import vizact
import vizinfo
import random


viz.setMultiSample(4)
viz.fov(60)
viz.go()

vizinfo.InfoPanel()
viz.clearcolor(viz.BLACK)

FRAME_RATE = 0.667 # in Hertz

r = list(range(7))
random.shuffle(r)
movieImages = viz.cycle( [ viz.addTexture('sequence_IMG/img%d.jpg' % i) for i in r ] )
screen = viz.addTexQuad()
screen.setPosition([0, 1.82, 1.5])
screen.setScale([4.0/3, 1, 1])

def executeExperiment():
for trialNumber in range(3):
yield Dark() #wait for doTrial to finish
yield vizact.ontimer(1.0/FRAME_RATE, NextMovieFrame)
print('Trial Done: ', trialNumber)

print('done with experiment')

#Setup timer to swap texture at specified frame rate
def NextMovieFrame():
screen.texture(movieImages.next())

def Dark():
yield viztask.waitTime(1) #wait for 1 second
viz.clearcolor(viz.BLACK)

vizact.ontimer(1.0/FRAME_RATE, NextMovieFrame)
viztask.schedule(executeExperiment())

:)

[Jeff]

Use viztask.waitTime instead of vizact.ontimer to wait inside of a task function. It seems like you can place the sequential actions in a single task function:
blankTexture = viz.addBlankTexture(size=(100,100))

def executeExperiment():
for trialNumber in range(3):
# Show blank texture for one second
screen.texture(blankTexture)
yield viztask.waitTime(1)

# Show movie texture for 1.5 seconds
screen.texture(movieImages.next())
yield viztask.waitTime(1.5)

print('Trial Done: ', trialNumber)
print('done with experiment')

[turinlife]

Thank you so much!
It is also possible to display the image from a folder randomly without rename all the images in the folder?
an alternative solution for this 3 lines
r = list(range(7))
random.shuffle(r)
movieImages = viz.cycle( [ viz.addTexture('sequence_IMG/img%d.jpg' % i) for i in r ] )
:confused::)