content: import sys
  import argparse
  import subprocess
  
  parser = argparse.ArgumentParser()
  parser.add_argument("verb", help="installed/missing")
  parser.add_argument(
      "packages", help="list of items to be there/not be there", nargs="+"
  )
  
  if __name__ == "__main__":
      args = parser.parse_args()
      installed = subprocess.check_output([sys.executable, "-m", "pip", "freeze"]).decode(
          "utf-8"
      )
      for pkg in args.packages:
          if args.verb == "missing":
              if pkg in installed:
                  raise ValueError(f"Expected {pkg} to not be installed.")
          if args.verb == "installed":
              if pkg not in installed:
                  raise ValueError(f"Expected {pkg} to be installed.")
  