Error when entering letter/character instead of number/integer

[helplessnoobb]

Hello all,
Excuse my complete lack of knowledge and "newbie-ness" as it has only been a few hours since I started my already rocky road to understanding Python.
I am going through some beginner's tutorials available on web and came up with "identification"-type of codes below:

The "ID number" or "idn" has to be a number between 0 and 10.

print("What is your ID number, " + str(name) + "?", end="  ")
idn=input()
while True:
    if int(idn) > 10 or int(idn) < 0:
        print("     ERROR: the ID number is a number between 0 to 10.", end="  ")
        idn=input()
        continue
    else:
        print("Thank you, no. " + str(idn))
        input()
        break

The code seemed to be working fine, but when I just got curious and entered a character/alphabet/word instead of a number, it gave me an error message. I'd like to show "ERROR: ID is a number, not a character," if a character/word is entered. Here is my try, but it has been unsuccessful so far.

print("What is your ID number, " + str(name) + "?", end="  ")
idn=input()
while True:
    if int(idn) > 10 or int(idn) < 0:
        print("     ERROR: the ID number is a number between 0 to 10.", end="  ")
        idn=input()
        continue
    if idn=str:
        print("     ERROR: ID is a number, not a character,", end="  ")
        idn=input()
        continue
    else:
        print("Thank you, no. " + str(idn))
        input()
        break

That "if idn=str:" is what I am struggling with. How can I set up that if-command? Thank you for your time! I'd really appreciate any advice!