> ## Documentation Index
> Fetch the complete documentation index at: https://docs.domino.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Read/Write to an object store

The API supports object store type datasources (such as S3) and allows for easy retrieval and upload of objects.

<Note>
  The following APIs are only available when using this type of datasource.
</Note>

## List

Get the datasource from the client:

```python theme={null}
from domino.data_sources import DataSourceClient

s3_dev = DataSourceClient().get_datasource("s3-dev")
```

```r theme={null}
library(DominoDataR)
client <- DominoDataR::datasource_client()
```

You can list objects available in the datasource. You can also specify a prefix:

```python theme={null}
objects = s3_dev.list_objects()

objects_under_path = s3_dev.list_objects("path_prefix")
```

```r theme={null}
keys <- DominoDataR::list_keys(client, "s3-dev")

keys_under_path <- DominoDataR::list_keys(client, "s3-dev", "path_prefix")
```

By default the number of returned objects is limited by the underlying datasource. You can specify how many keys you want as an optional parameter:

```python theme={null}
objects = s3_dev.list_objects(page_size = 1500)
```

```r theme={null}
keys = DominoDataR::list_keys(client, "s3-dev", page_size = 1500)
```

## Read

You can get object content, without having to create object entities, by using the datasource API and specifying the `Object` key name:

```python theme={null}
# Get content as binary
content = s3_dev.get("key")

# Download content to file
s3_dev.download_file("key", "./path/to/local/file")

# Download content to file-like object
f = io.BytesIO()
s3_dev.download_fileobj("key", f)
```

```r theme={null}
# Get content as raw vector
content <- DominoDataR::get_object(client, "s3-dev", "key")

# Get content as character vector
content <- DominoDataR::get_object(client, "s3-dev", "key", as = "text")

# Download content to file
DominoDataR::save_object(client, "s3-dev", "key", "./path/to/local/file")
```

You can also get the datasource entity content from an object entity (Python only):

```python theme={null}
# Key object
my_key = s3_dev.Object("key")

# Get content as binary
content = my_key.get()

# Download content to file
my_key.download_file("./path/to/local/file")

# Download content to file-like object
f = io.BytesIO()
my_key.download_fileobj(f)
```

## Write

Similar to the read/get APIs, you can also write data to a specific object key. From the datasource:

```python theme={null}
# Put binary content to given object key
s3_dev.put("key", b"content")

# Upload file content to specified object key
s3_dev.upload_file("key", "./path/to/local/file")

# Upload file-like content to specified object key
f = io.BytesIO(b"content")
s3_dev.upload_fileobj("key", f)
```

```r theme={null}
# Put raw or character vector to object key
DominoDataR::put_object(client, "s3-dev", "key", what = "content")

# Upload file content to specified object key
DominoDataR::upload_object(client, "s3-dev", "key", file = "./path/to/local/file")
```

You can also write from the object entity (Python only).

```python theme={null}
# Key object
my_key = s3_dev.Object("key")

# Put content as binary
my_key.put(b"content")

# Upload content from file
my_key.upload_file("./path/to/local/file")

# Upload content from file-like object
f = io.BytesIO()
my_key.upload_fileobj(f)
```