import random

used = set()
for i in range(0, 10):
    # Get a random row from my database
    bank_account = random_table_row(datatablebootstrap.BankAccount)
    # Generate a random check number from 10 to 50
    check_number = str(random.randrange(10, 50))
    # Until the combination of bank_account.id and check_number is unique, keep getting another check_number
    while ((bank_account.id, check_number) in used):
        check_number = str(random.randrange(10, 50))

    # populate the database with the new check data
    new_check(bank_account.id, check_number)
    # add the 2-tuple to the set of used 2-tuples so it will not be used again
    used.add((bank_account.id, check_number))