## build_error_rows_spec()


Return an asset spec that adds an asset's error rows to the asset graph.


Usage

``` python
build_error_rows_spec(
    schema,
    asset,
    *,
    partitions_def=None,
    group_name=None,
    owners=None,
    tags=None
)
```


The asset writes the error rows whether or not the spec exists.


## Parameters


`schema: type[dy.Schema]`  
The asset's schema. The spec's Columns tab has its columns, then one rule column per rule.

`asset: dg.AssetsDefinition | dg.AssetKey | str | Sequence[str]`  
The asset the error rows came from, as its definition or its asset key. Pass a key only for an asset you cannot import. A definition also sets the spec's partitions, group, owners and tags, and the error-rows key, IO manager key and definition metadata of its writer.

`partitions_def: dg.PartitionsDefinition | None = None`  
The error rows' partitions, when [asset](asset.md#dagster_dataframely.asset) is a key.

`group_name: str | None = None`  
The error rows' asset group. A definition's group is the default, and a value overrides it. Unlike `partitions_def`, passing it with a definition does not raise, because the group sets only where the catalog lists the error rows.

`owners: Sequence[str] | None = None`  
The error rows' owners. A definition's owners are the default, and a value replaces them, as `group_name` does.

`tags: Mapping[str, str] | None = None`  
The error rows' tags. A definition's tags are the default, and a value replaces them, as `group_name` does.


## Returns


`dg.AssetSpec`  
A spec keyed by the error-rows key that depends on [asset](asset.md#dagster_dataframely.asset), to pass to `dg.Definitions(assets=[...])`.


## Raises


`ReservedColumnError`  
A column name is in the reserved `dy_` namespace.

`InvalidColumnNameError`  
A column name has a character Dagster does not allow in an asset check name.

`CheckNameCollisionError`  
Two rules produce the same asset check name.

`InvalidSeverityError`  
The schema declares a severity this package cannot read.

`dg.DagsterInvariantViolationError`  
[asset](asset.md#dagster_dataframely.asset) is a definition and the call also passes `partitions_def`.


## Examples


``` python
import polars as pl

import dagster_dataframely as dd
from dagster_dataframely.data import OrdersSchema


@dd.asset(OrdersSchema, filter=True)
def orders(raw_orders: pl.DataFrame) -> pl.DataFrame:
    return raw_orders


dd.build_error_rows_spec(OrdersSchema, orders).key
```


    AssetKey(['orders__error_rows'])


Pass the spec, not its key, to `dg.Definitions(assets=[...])` with `orders`. A downstream asset can then declare the error rows as an input.