input: from typing import List
  
  def find_primes(n: int) -> List[int]:
      """ Find all prime numbers up to a given number n and return them as a list.
      >>> find_primes(10)
      [2, 3, 5, 7]
      >>> find_primes(20)
      [2, 3, 5, 7, 11, 13, 17, 19]
      """
  
  def is_prime(num: int) -> bool:
      # 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
  
  # Intialize an empty list to store prime numbers
  prime_numbers = []
  
  # Iterate from 2 to n
  for n in range(2, n + 1):
      # Check if the number is prime
      if is_prime(n):
          prime_numbers.append(n)
          
  return prime_numbers
output:     prime_numbers = []
  
      # Iterate from 2 to n
      for n in range(2, n + 1):
          # Check if the number is prime
          if is_prime(n):
              prime_numbers.append(n)
              
      return prime_numbers