flatten_metadata
======================================

.. py:function:: petpal.utils.image_io.flatten_metadata(metadata: dict) -> dict

   Given a metadata dictionary, return an identical dictionary with any list-like or dict-like
   data replaced with individual values. Useful when converting several JSON files into a TSV
   file.

   :param metadata: The metadata file that may contain lists of data.
   :type metadata: dict

   :returns: *metadata_for_tsv (dict)* --

             The same metadata with list-like data replaced with individual
                 values.

   .. note::

      List-like data is replaced by renaming the key it appears in with ordinal values. E.g. if
      metadata contains a key named ``FitPars`` with value [4,6] then the function would create
      two new keys, FitPars_1 and Fit_Pars2 with values 4 and 6 respectively. Likewise, nested
      dictionaries are replaced by combining the two keys identifying the data with underscores.
      Function is not robust for doubly nested lists and dictionaries.