input: Write a python function to determine the type of a character (uppercase, lowercase, digit, special character).
  assert char_type('A') == 'Uppercase'
  assert char_type('a') == 'Lowercase'
  assert char_type('1') == 'Digit'
  assert char_type('@') == 'Special Character'
output: def char_type(c):
      if 'A' <= c <= 'Z':
          return 'Uppercase'
      elif 'a' <= c <= 'z':
          return 'Lowercase'
      elif '0' <= c <= '9':
          return 'Digit'
      else:
          return 'Special Character'