code: def python_sidebar_navigation(python_input):
      
      def get_text_fragments():
          tokens = []
  
          # Show navigation info.
          tokens.extend([
              ('class:sidebar', '    '),
              ('class:sidebar.key', '[Arrows]'),
              ('class:sidebar', ' '),
              ('class:sidebar.description', 'Navigate'),
              ('class:sidebar', ' '),
              ('class:sidebar.key', '[Enter]'),
              ('class:sidebar', ' '),
              ('class:sidebar.description', 'Hide menu'),
          ])
  
          return tokens
  
      return Window(
          FormattedTextControl(get_text_fragments),
          style='class:sidebar',
          width=Dimension.exact(43),
          height=Dimension.exact(1))
docs: Create the `Layout` showing the navigation information for the sidebar.