from blinkstick import blinkstick
bstick = blinkstick.find_first()
while x < 31:
bstick.set_color(channel=0, index=x, name="red")
That should light all the LEDs on the Flex, although you will need to indent the last two lines which are inside the while loop - I can’t work out how to add a tab on here.
Arvydas also has some example Python code stored here which may be helpful for testing.