code: def short_form_one_format(jupytext_format):
      """Represent one jupytext format as a string"""
      if not isinstance(jupytext_format, dict):
          return jupytext_format
      fmt = jupytext_format["extension"]
      if "suffix" in jupytext_format:
          fmt = jupytext_format["suffix"] + fmt
      elif fmt.startswith("."):
          fmt = fmt[1:]
  
      if "prefix" in jupytext_format:
          fmt = jupytext_format["prefix"] + "/" + fmt
  
      if jupytext_format.get("format_name"):
          if jupytext_format["extension"] not in [
              ".md",
              ".markdown",
              ".Rmd",
          ] or jupytext_format["format_name"] in [
              "pandoc",
              MYST_FORMAT_NAME,
          ]:
              fmt = fmt + ":" + jupytext_format["format_name"]
  
      return fmt
  
imports: import os
  import re
  import warnings
  import nbformat
  import yaml
  from .cell_reader import DoublePercentScriptCellReader, HydrogenCellReader, LightScriptCellReader, MarkdownCellReader, RMarkdownCellReader, RScriptCellReader, SphinxGalleryScriptCellReader
  from .cell_to_text import BareScriptCellExporter, DoublePercentCellExporter, HydrogenCellExporter, LightScriptCellExporter, MarkdownCellExporter, RMarkdownCellExporter, RScriptCellExporter, SphinxGalleryCellExporter
  from .header import header_to_metadata_and_cell, insert_or_test_version_number
  from .languages import _COMMENT_CHARS, _SCRIPT_EXTENSIONS, same_language
  from .magics import is_magic
  from .metadata_filter import metadata_filter_as_string
  from .myst import MYST_FORMAT_NAME, is_myst_available, matches_mystnb, myst_extensions, myst_version
  from .pandoc import is_pandoc_available, pandoc_version
  from .stringparser import StringParser
  from .version import __version__
label_desc: Use image node_id 13 for calling a global function with example usage: short_form_one_format(jupytext_format) and returns: fmt, jupytext_format