Having two standards for a keypad layout is inconvenient!  
Computer keypad's layout:  


 
Cell phone keypad's layout:  


Solve the horror of unstandartized keypads by providing a function that converts computer input to a number as if it was typed by a phone.

Example:  
"789" -> "123"

Notes:  
You get a string with numbers only

Difficulty: introductory

Starter code:

def computer_to_phone(numbers):
	

Solutions:
def computer_to_phone(numbers):
  return "".join([str({0:0, 1:7, 2:8, 3:9, 4:4, 5:5, 6:6, 7:1, 8:2, 9:3}[int(n)]) for n in numbers])

def computer_to_phone(numbers):
    return numbers.translate(str.maketrans('123789', '789123'))

tbl = str.maketrans('789456123', '123456789')

def computer_to_phone(numbers):
    return numbers.translate(tbl)

def computer_to_phone(numbers):
    conversion = "0789456123"
    return "".join([conversion[int(x)] for x in numbers])

def computer_to_phone(numbers):
    pad = {
        "7":"1",
        "8":"2",
        "9":"3",
        "4":"4",
        "5":"5",
        "6":"6",
        "1":"7",
        "2":"8",
        "3":"9",
        "0":"0"
    }
    return "".join([pad[number] for number in numbers])

def computer_to_phone(numbers):
    d = {'7':'1', '8':'2','9':'3','4':'4','5':'5','6':'6','1':'7','2':'8','3':'9','0':'0'}
    return ''.join( [ d[c] if c in d else c for c in numbers ] )