code: def safe_makedir(dname):
      
      if not dname:
          return dname
      num_tries = 0
      max_tries = 5
      while not os.path.exists(dname):
          # we could get an error here if multiple processes are creating
          # the directory at the same time. Grr, concurrency.
          try:
              os.makedirs(dname)
          except OSError:
              if num_tries > max_tries:
                  raise
              num_tries += 1
              time.sleep(2)
      return dname
docs: Make a directory if it doesn't exist, handling concurrent race conditions.