## read_mapping()


Read a JSON mapping file and parse its content into DataFrames.


Usage

``` python
read_mapping(path)
```


The function processes JSON data with four main keys:

    1. ``schema_version``: The version of the mapping schema.
    2. ``dsd_id``: The Data Structure Definition ID.
    3. ``components``: A flat structure converted into a DataFrame.
    4. ``representation``: Multiple sub-keys, each converted into a
       separate DataFrame. Empty sub-keys are skipped.

All occurrences of the string `"NA"` are converted to `pd.NA`.


## Parameters


`path: str | Path`  
The file path to the JSON file to be parsed.


## Returns


`dict[str, str | pd.DataFrame]`  
A dictionary where:

- `schema_version` is stored under key `'schema_version'`.
- `dsd_id` is stored under key `'dsd_id'`.
- The components DataFrame is stored under key `'components'`.
- Each valid representation sub-key is stored as a DataFrame under its corresponding key.


## Raises


`ValueError`  
If required keys are missing or have unexpected formats.