input: 
  # Function to generate prime numbers between 1 and a given number n 
  def generate_prime_numbers(n): 
    
      # Array for checking if a number is prime or not
      prime_list = [True for i in range(n + 1)] 
      p = 2
      while (p * p <= n): 
            
          # If prime_list[p] is not changed, then it is a prime 
          if (prime_list[p] == True): 
                
              # Update all multiples of p 
              for i in range(p * 2, n + 1, p): 
                  prime_list[i] = False
          p += 1
    
      # Collecting prime numbers 
      prime_numbers = []
      for p in range(2, n): 
          if prime_list[p]: 
              prime_numbers.append(p)
      return prime_numbers
  
  # Test cases
  print(generate_prime_numbers(10))  # Output: [2, 3, 5, 7]
  print(generate_prime_numbers(20))  # Output: [2, 3, 5, 7, 11, 13, 17, 19]
  print(generate_prime_numbers(5))   # Output: [2, 3]
  
output:     
      prime_list[0] = prime_list[1] = False
      return prime_numbers
  