input: Write a function to capitalize each character in a string and another function to uncapitalize each character.
  assert capitalize_each_character('hello') == 'HELLO'
  assert capitalize_each_character('world') == 'WORLD'
  assert uncapitalize_each_character('HELLO') == 'hello'
  assert uncapitalize_each_character('WORLD') == 'world'
output: def capitalize_each_character(s):
      return s.upper()
  
  def uncapitalize_each_character(s):
      return s.lower()