old_contents: """ Filesystem utilities
  """
  import contextlib
  import os
  
  RUN_RE = '\d{6}_[a-zA-Z\d\-]+_\d{4}_[AB][A-Z\d]{9}'
  
  @contextlib.contextmanager
  def chdir(new_dir):
      """Context manager to temporarily change to a new directory.
      """
      cur_dir = os.getcwd()
      # This is weird behavior. I'm removing and and we'll see if anything breaks.
      #safe_makedir(new_dir)
      os.chdir(new_dir)
      try:
          yield
      finally:
          os.chdir(cur_dir)
  
new_contents: """ Filesystem utilities
  """
  import contextlib
  import os
  
  RUN_RE = '\d{6}_[a-zA-Z\d\-]+_\d{4}_[AB0][A-Z\d]'
  
  @contextlib.contextmanager
  def chdir(new_dir):
      """Context manager to temporarily change to a new directory.
      """
      cur_dir = os.getcwd()
      # This is weird behavior. I'm removing and and we'll see if anything breaks.
      #safe_makedir(new_dir)
      os.chdir(new_dir)
      try:
          yield
      finally:
          os.chdir(cur_dir)
  
subject: Modify regexp to pick up MiSeqs as well. Thanks @senthil10