## io.VersionedSource


What a pipeline needs of a source: a table with integer versions that


Usage

``` python
io.VersionedSource()
```


hands out its snapshot and its change between two versions. Delta and Iceberg tables implement it (`sverify.io`).

Sources you write yourself usually subclass [sverify.io.Source](io.Source.md#sverify.io.Source) instead, which implements this protocol on top of one [read](odcs.read.md#sverify.odcs.read) method. Implement it directly for a table format with metadata facts and a change feed; [SourceBatch.from_changes](io.SourceBatch.md#sverify.io.SourceBatch.from_changes) and [from_snapshot](io.SourceBatch.md#sverify.io.SourceBatch.from_snapshot) build what [changes](io.Source.md#sverify.io.Source.changes) returns.


## Attributes


`name: str`  
The table's name in the plans that read it.


## Attributes

| Name | Description |
|----|----|
| [name](#name) | The table's name in the views that read it. |

------------------------------------------------------------------------


#### name


The table's name in the views that read it.


`name: str`


## Methods

| Name | Description |
|----|----|
| [changes()](#changes) | The change from version `since` to `until` (default: the latest). |
| [latest()](#latest) | The table's latest version. |
| [schema()](#schema) | The table's schema at its latest version. |
| [snapshot()](#snapshot) | The table at `version`, or at its latest version. |

------------------------------------------------------------------------


#### changes()


The change from version `since` to `until` (default: the latest).


Usage

``` python
changes(since, until=None)
```


------------------------------------------------------------------------


#### latest()


The table's latest version.


Usage

``` python
latest()
```


------------------------------------------------------------------------


#### schema()


The table's schema at its latest version.


Usage

``` python
schema()
```


------------------------------------------------------------------------


#### snapshot()


The table at `version`, or at its latest version.


Usage

``` python
snapshot(version=None)
```