> For the complete documentation index, see [llms.txt](https://docs.feast.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.feast.dev/v0.19-branch/reference/data-sources/file.md).

# File

## Description

File data sources allow for the retrieval of historical feature values from files on disk for building training datasets, as well as for materializing features into an online store.

{% hint style="warning" %}
FileSource is meant for development purposes only and is not optimized for production use.
{% endhint %}

## Example

```python
from feast import FileSource
from feast.data_format import ParquetFormat

parquet_file_source = FileSource(
    file_format=ParquetFormat(),
    file_url="file:///feast/customer.parquet",
)
```

Configuration options are available [here](https://rtd.feast.dev/en/latest/index.html#feast.data_source.FileSource).


---

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