input: Write a python function to count the number of odd numbers in a given range.
  assert odd_count(1, 10) == 5
  assert odd_count(10, 20) == 5
  assert odd_count(21, 30) == 5
output: def odd_count(start, end):
      return len([i for i in range(start, end + 1) if i % 2 != 0])