input: Write a function to generate a prime number sequence using Python. This function should take an integer `n` as input and print all prime numbers less than or equal to `n`. Use the Sieve of Eratosthenes algorithm to generate the sequence. If `n` is less than 2, the function should print nothing.
  
  def generate_prime_numbers(n): 
          primes = [True for i in range(n + 1)] 
          p = 2
          while (p * p <= n): 
              if (primes[p] == True): 
                  for i in range(p * p, n + 1, p): 
                      primes[i] = False
              p += 1
          primes[0] = False
          primes[1] = False
          for p in range(n + 1): 
              if primes[p]: 
                  print(p)
  
  assert generate_prime_numbers(10) == '''2
  3
  5
  7'''
  assert generate_prime_numbers(20) == '''2
  3
  5
  7
  11
  13
  17
  19'''
  assert generate_prime_numbers(1) == ''
  assert generate_prime_numbers(0) == ''
output: def generate_prime_numbers(n): 
      if n < 2:
          return
      primes = [True for i in range(n + 1)] 
      p = 2
      while (p * p <= n): 
          if (primes[p] == True): 
              for i in range(p * p, n + 1, p): 
                  primes[i] = False
          p += 1
      primes[0] = False
      primes[1] = False
      for p in range(n + 1): 
          if primes[p]: 
              print(p)