input: Write a function to generate a unique 6 digit number.
  
  def generate_number():
      random_number = random.randint(10000, 99999)
      return random_number
  
  assert generate_number() >= 10000 and generate_number() <= 99999
  assert generate_number() != generate_number()  # Due to the nature of random numbers, this will not be a true equality
output: import random
  
  def generate_number():
      return random.randint(100000, 999999)