# CassandraLoader

> **Class** in `langchain_community`

📖 [View in docs](https://reference.langchain.com/python/langchain-community/document_loaders/cassandra/CassandraLoader)

## Signature

```python
CassandraLoader(
    self,
    table: Optional[str] = None,
    session: Optional[Session] = None,
    keyspace: Optional[str] = None,
    query: Union[str, Statement, None] = None,
    page_content_mapper: Callable[[Any], str] = str,
    metadata_mapper: Callable[[Any], dict] = lambda _: {},
    *,
    query_parameters: Union[dict, Sequence, None] = None,
    query_timeout: Optional[float] = _NOT_SET,
    query_trace: bool = False,
    query_custom_payload: Optional[dict] = None,
    query_execution_profile: Any = _NOT_SET,
    query_paging_state: Any = None,
    query_host: Optional[Host] = None,
    query_execute_as: Optional[str] = None,
)
```

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| `table` | `Optional[str]` | No | The table to load the data from. (do not use together with the query parameter) (default: `None`) |
| `session` | `Optional[Session]` | No | The cassandra driver session. If not provided, the cassio resolved session will be used. (default: `None`) |
| `keyspace` | `Optional[str]` | No | The keyspace of the table. If not provided, the cassio resolved keyspace will be used. (default: `None`) |
| `query` | `Union[str, Statement, None]` | No | The query used to load the data. (do not use together with the table parameter) (default: `None`) |
| `page_content_mapper` | `Callable[[Any], str]` | No | a function to convert a row to string page content. Defaults to the str representation of the row. (default: `str`) |
| `metadata_mapper` | `Callable[[Any], dict]` | No | a function to convert a row to document metadata. (default: `lambda _: {}`) |
| `query_parameters` | `Union[dict, Sequence, None]` | No | The query parameters used when calling session.execute . (default: `None`) |
| `query_timeout` | `Optional[float]` | No | The query timeout used when calling session.execute . (default: `_NOT_SET`) |
| `query_trace` | `bool` | No | Whether to use tracing when calling session.execute . (default: `False`) |
| `query_custom_payload` | `Optional[dict]` | No | The query custom_payload used when calling session.execute . (default: `None`) |
| `query_execution_profile` | `Any` | No | The query execution_profile used when calling session.execute . (default: `_NOT_SET`) |
| `query_host` | `Optional[Host]` | No | The query host used when calling session.execute . (default: `None`) |
| `query_execute_as` | `Optional[str]` | No | The query execute_as used when calling session.execute . (default: `None`) |

## Extends

- `BaseLoader`

## Constructors

```python
__init__(
    self,
    table: Optional[str] = None,
    session: Optional[Session] = None,
    keyspace: Optional[str] = None,
    query: Union[str, Statement, None] = None,
    page_content_mapper: Callable[[Any], str] = str,
    metadata_mapper: Callable[[Any], dict] = lambda _: {},
    *,
    query_parameters: Union[dict, Sequence, None] = None,
    query_timeout: Optional[float] = _NOT_SET,
    query_trace: bool = False,
    query_custom_payload: Optional[dict] = None,
    query_execution_profile: Any = _NOT_SET,
    query_paging_state: Any = None,
    query_host: Optional[Host] = None,
    query_execute_as: Optional[str] = None,
) -> None
```

| Name | Type |
|------|------|
| `table` | `Optional[str]` |
| `session` | `Optional[Session]` |
| `keyspace` | `Optional[str]` |
| `query` | `Union[str, Statement, None]` |
| `page_content_mapper` | `Callable[[Any], str]` |
| `metadata_mapper` | `Callable[[Any], dict]` |
| `query_parameters` | `Union[dict, Sequence, None]` |
| `query_timeout` | `Optional[float]` |
| `query_trace` | `bool` |
| `query_custom_payload` | `Optional[dict]` |
| `query_execution_profile` | `Any` |
| `query_paging_state` | `Any` |
| `query_host` | `Optional[Host]` |
| `query_execute_as` | `Optional[str]` |


## Properties

- `query`
- `metadata`
- `session`
- `page_content_mapper`
- `metadata_mapper`
- `query_kwargs`

## Methods

- [`lazy_load()`](https://reference.langchain.com/python/langchain-community/document_loaders/cassandra/CassandraLoader/lazy_load)
- [`alazy_load()`](https://reference.langchain.com/python/langchain-community/document_loaders/cassandra/CassandraLoader/alazy_load)

---

[View source on GitHub](https://github.com/langchain-ai/langchain-community/blob/4b280287bd55b99b44db2dd849f02d66c89534d5/libs/community/langchain_community/document_loaders/cassandra.py#L27)