input: Write a function to find all the prime numbers up to a given number 'n'. The function should return a list of prime numbers.
  
  def find_primes(n):
      def is_prime(num):
          # Iterate from 2 to the square root of the number
          for i in range(2, int(num ** 0.5) + 1):
              if num % i == 0:
                  return False
          return True
  
      primes = []
      # Iterate from 2 to n
      for num in range(2, n+1):
          # Check if the number is prime
          if is_prime(num):
              primes.append(num)
      return primes
  
  assert find_primes(10) == [2, 3, 5, 7]
  assert find_primes(20) == [2, 3, 5, 7, 11, 13, 17, 19]
  assert find_primes(2) == [2]
  assert find_primes(1) == []
  assert find_primes(0) == []
output: def find_primes(n):
      def is_prime(num):
          for i in range(2, int(num ** 0.5) + 1):
              if num % i == 0:
                  return False
          return True
  
      primes = []
      for num in range(2, n+1):
          if is_prime(num):
              primes.append(num)
      return primes