## standardize_output()


Standardize the output DataFrame by adding SDMX reference columns.


Usage

``` python
standardize_output(
    df,
    artefact_id,
    schema,
    action="I",
)
```


Enriches the given DataFrame with SDMX-related metadata columns (`STRUCTURE`, `STRUCTURE_ID`, `ACTION`) based on the provided artefact ID and schema, then ensures these columns appear first.


## Parameters


`df: pd.DataFrame`  
Input DataFrame containing SDMX data.

`artefact_id: str`  
Unique identifier of the SDMX artefact (e.g., Dataflow ID).

`schema: Schema`  
A pysdmx Schema object used to determine artefact type and filter columns.

`action: Literal[``"I", `<span class="st">`"U"``, ``"D"``]`</span>` = ``"I"`  
Action indicator for SDMX operations. Defaults to `"I"`. Allowed values: `"I"` (Insert), `"U"` (Update), `"D"` (Delete).


## Returns


`pd.DataFrame`  
A new DataFrame with SDMX reference columns added and reordered.


## Raises


`ValueError`  
If `df` is empty or `artefact_id`/`schema` is empty.

`TypeError`  
If `df` is not a pandas DataFrame.