[SOLVED] How do I convert my traffic signal python script into a bash script?

I would like to convert the following code to bash:

Code:from random import randrange

Red = 1
Yellow = 2
Green = 3

def process_light(x):
if x == Red:
print("red light")
return Green

elif x == Yellow:
print("yellow light")
return Red

elif x == Green:
print("green light")
return Yellow

generatedLight = randrange(1, 4)
while True:
generatedLight = process_light(generatedLight)