old_contents: import click
  from tabulate import tabulate
  
  from EasyEuler import data
  
  
  @click.command()
  @click.option('--sort', '-s', type=click.Choice(['id', 'difficulty']),
                default='id', help='Sort the list by problem attribute.')
  def cli(sort):
      """ Lists all available problems. """
  
      problems = sorted(data.problems, key=lambda p: p[sort.lower()])
      problem_list = [(problem['id'], problem['name'], problem['difficulty'])
                      for problem in problems]
  
      problem_table = tabulate(problem_list, ['ID', 'Name', 'Difficulty'],
                               tablefmt='fancy_grid')
      click.echo_via_pager(problem_table)
  
new_contents: import click
  from tabulate import tabulate
  
  from EasyEuler import data
  
  
  @click.command()
  @click.option('--sort', '-s', type=click.Choice(['id', 'difficulty']),
                default='id', help='Sort the list by problem attribute.')
  def cli(sort):
      """ Lists all available problems. """
  
      problems = sorted(data.problems, key=lambda p: p[sort.lower()])
      problem_list = [(problem['id'], problem['name'],
                       '%d%%' % problem['difficulty']) for problem in problems]
  
      problem_table = tabulate(problem_list, ['ID', 'Name', 'Difficulty'],
                               tablefmt='fancy_grid')
      click.echo_via_pager(problem_table)
  
subject: Add percentage sign to difficulty