如何将以下 Python 脚本转换为 Bash 脚本？

Question

I am trying to convert the following Python Script into a Bash Script. I am not sure how to fix my bash code so it can follow the rules set in the Python Script. I tried creating a function in the Bash Script to enforce the rules, but I keep recieving errors.

Python Code

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)

My Bash Code

function number {
         return $[ `shuf -i 1-3 -n 1` ]
}

state=1

function colors {
         if x == 3:
         return 1
         elif x == 2:
         return 3
         elif x == 1:
         return 2
         fi
}

while [ 1 ]
do
      colors
      case $? in
      1)
              echo "The light is Green";;
      2)
              echo "The light is Yellow";;
      3)
              echo "The light is Red";;
      esac
      sleep 5
done

Answer 1

You were very close... here is the correctly translated bash script:

#!/bin/bash

function number {
  echo $[ `shuf -i 1-3 -n 1` ]
}

state=$(number)

colors () {
  if [ $1 == 3 ]; then
    echo 1
  elif [ $1 == 2 ]; then
    echo 3
  elif [ $1 == 1 ]; then
    echo 2
  fi
}

while [ 1 ]
do
      state=$(colors $state)
      case $state in
      1)
              echo "The light is Green";;
      2)
              echo "The light is Yellow";;
      3)
              echo "The light is Red";;
      esac

      sleep 5
done

Result:

The light is Yellow

The light is Red

The light is Green

The light is Yellow

...

Answer 2

This behaves the same way as your original python script. The rules function takes an argument. This argument is the ${1} in the function. I use the random number as the argument. Best of luck.

function number 
    {   
    echo $[ `shuf -i 1-3 -n 1` ]
    }   

function rules
    {   
    case "${1}" in
        1)  
            echo "The light is green.";;
        2)  
            echo "The light is yellow.";;
        3)  
            echo "The light is red.";;
    esac
    }   

while [ 1 ] 
do
    rules $(number)
done