input: Write a function to find prime numbers in a given range.
  assert find_primes(20, 51) == [23, 29, 31, 37, 41, 43, 47]
  assert find_primes(10, 30) == [11, 13, 17, 19, 23, 29]
  assert find_primes(50, 60) == [53, 59]
output: def find_primes(start, end):
      def is_prime(n):
          if n <= 1:
              return False
          for i in range(2, int(n**0.5) + 1):
              if n % i == 0:
                  return False
          return True
      
      return [num for num in range(start, end) if is_prime(num)]