input: Write a function to take a number and return a list of all the divisors of that number. If the number is less than 1, return an empty list.
  assert get_divisors(12)==[1, 2, 3, 4, 6, 12]
  assert get_divisors(7)==[1, 7]
  assert get_divisors(0)==[]
  assert get_divisors(-5)==[]
  assert get_divisors(1)==[1]
output: def get_divisors(n):
      if n < 1:
          return []
      divisors = []
      for i in range(1, n + 1):
          if n % i == 0:
              divisors.append(i)
      return divisors