Python: Receiving (ValueError: {error} not in list) while {error} is in the list in any form

I wanted to make a code which make a list containing numbers and upper cases I am too lazy so I did this

import string
List1= [string.digits+string.ascii_uppercase]

And then one of my code will separate my input into every single unit, and then make them into the list number of the list {List1}

def get_ID(NotlistNum):
  num = []
  NotlistNum = NotlistNum.upper()
  for digits in NotlistNum:
    if digits == '.':
      DotPosit = len(num)
    else:
      num.append(List1.index(digits))
  return [num, DotPosit]

And then, run this

InputID=input(‘enter your ID: ‘)
InputID=InputID.upper()
print(get_ID(InputID))

But when I run it, this happened

enter your ID: 2
Traceback (most recent call last):
  File “main.py”, line 13, in <module>
    print(get_ID(InputID))
  File “main.py”, line 10, in get_ID
    num.append(List1.index(digits))
ValueError: ‘2’ is not in list

I then tried to makeList1= [‘0’, ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, ‘9’+string.ascii_uppercase but same error occurs. Anyone can help me find where the problem is?