Generate a Unique String in Python/Django

Question

What I want is to generate a string(key) of size 5 for my users on my website. More like a BBM PIN.

The key will contain numbers and uppercase English letters:

Answer 1

Am not sure about any short cryptic ways, but it can be implemented using a simple straight forward function assuming that you save all the generated strings in a set:

import random

def generate(unique):
    chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
    while True:
        value = "".join(random.choice(chars) for _ in range(5))
        if value not in unique:
            unique.add(value)
            break

unique = set()
for _ in range(10):
    generate(unique)