new_contents: import sys
  from github import Github
  
  if len(sys.argv) == 2:
      repository = sys.argv[1]
  elif len(sys.argv) > 2:
      print("Usage: next_pr_number.py <repository>")
      sys.exit(1)
  else:
      repository = 'astropy/astropy'
  
  gh = Github()
  repo = gh.get_repo('astropy/astropy')
  pl = repo.get_issues(sort='created', state='all')
  print("Next PR number: {0}".format(pl.get_page(0)[0].number))
  
subject: Add a script to find the next PR number for the changelog