Run phase

import pygame
from openexp.exceptions import response_error
# Start by playing the sound file:
my_sampler.play()
sampler_paused = False
for i in range(len(patch_list)):
    if sampler_paused:
        my_sampler.resume()
    # Determine the stimulus by selecting one item from the
    # stimulus list (without replacement).
    stim = patch_list.pop()
    # Set the stimulus for future use in the GUI (notably, the logger
    # item):
    exp.set("stim", stim)
    # Determine the absolute path to the image in
    # the file pool:
    path = exp.get_file(stim)
    # Show the stimulus:
    # Start with a gray background for a certain duration:
    my_canvas.clear()
    # We have to draw something in order to clear the background.
    my_canvas.circle(0,0,0,color=self.get('background'))
    my_canvas.show()
    self.sleep(100)
    # Present the patch
    my_canvas.image(path)
    my_canvas.show()
    start_time = self.time()
    time_passed = 0
    while time_passed < ISI:
        # Keep checking whether the duration  of this
        # while loop is still below the maximum duration
        # (i.e. ISI).
        time_passed = self.time()-start_time
        print time_passed
        # To poll the keyboard and mouse at the same time, we use pygame
        # directly. This means that this piece of code requires the xpyriment
        # or pygame backend! See:
        # <http://www.pygame.org/docs/ref/event.html>
        button = False
        key = False
        # Loop through all 'events', which are key presses or button clicks
        for event in pygame.event.get([pygame.MOUSEBUTTONDOWN, pygame.KEYDOWN]):
            if event.type == pygame.MOUSEBUTTONDOWN:
                button = True
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_ESCAPE:
                    raise response_error("The escape key was pressed.")
                elif event.key == pygame.K_SPACE:
                    key = True
        # If a key was pressed or a button was clicked, exit the loop
        if button or key:
            break
    # Set the given responses so that they will be logged by
    # the logger item. Note that for the variable "mouse_click" (see below)
    # True' indicates that a mouse click was given, whereas'False'
    # indicates that no mouse response was given. This, in combination
    # with the variable 'stim', will enable you to evaluate participants'
    # performance (i.e. whether a mouse click was correct or a false alarm, etc.):
    exp.set("mouse_click", button)
    # If a mouse response was collected, the for loop will be
    # continued. However, if the spacebar was pressed, we need to
    # do something else:
    if key:
        # Pause the sampler:
        my_sampler.pause()
        sampler_paused = True
        # Show the in-the-GUI-prepared form items:
        self.experiment.items['mc'].prepare()
        self.experiment.items['mc'].run()
    # Finally, log the responses:
    self.experiment.items['logger'].prepare()
    self.experiment.items['logger'].run()
    # And set the variable 'form_response' to 'NA' again.
    exp.set('form_response', "NA")