langchain/docs/ecosystem/unstructured.md
Matt Robinson 3dfe1cf60e
feat: document loader for epublications (#2202)
### Summary

Adds a new document loader for processing e-publications. Works with
`unstructured>=0.5.4`. You need to have
[`pandoc`](https://pandoc.org/installing.html) installed for this loader
to work.

### Testing

```python
from langchain.document_loaders import UnstructuredEPubLoader

loader = UnstructuredEPubLoader("winter-sports.epub", mode="elements")
data = loader.load()
data[0]
```
2023-03-30 20:45:31 -07:00

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Markdown

# Unstructured
This page covers how to use the [`unstructured`](https://github.com/Unstructured-IO/unstructured)
ecosystem within LangChain. The `unstructured` package from
[Unstructured.IO](https://www.unstructured.io/) extracts clean text from raw source documents like
PDFs and Word documents.
This page is broken into two parts: installation and setup, and then references to specific
`unstructured` wrappers.
## Installation and Setup
- Install the Python SDK with `pip install "unstructured[local-inference]"`
- Install the following system dependencies if they are not already available on your system.
Depending on what document types you're parsing, you may not need all of these.
- `libmagic-dev` (filetype detection)
- `poppler-utils` (images and PDFs)
- `tesseract-ocr`(images and PDFs)
- `libreoffice` (MS Office docs)
- `pandoc` (EPUBs)
- If you are parsing PDFs using the `"hi_res"` strategy, run the following to install the `detectron2` model, which
`unstructured` uses for layout detection:
- `pip install "detectron2@git+https://github.com/facebookresearch/detectron2.git@v0.6#egg=detectron2"`
- If `detectron2` is not installed, `unstructured` will fallback to processing PDFs
using the `"fast"` strategy, which uses `pdfminer` directly and doesn't require
`detectron2`.
## Wrappers
### Data Loaders
The primary `unstructured` wrappers within `langchain` are data loaders. The following
shows how to use the most basic unstructured data loader. There are other file-specific
data loaders available in the `langchain.document_loaders` module.
```python
from langchain.document_loaders import UnstructuredFileLoader
loader = UnstructuredFileLoader("state_of_the_union.txt")
loader.load()
```
If you instantiate the loader with `UnstructuredFileLoader(mode="elements")`, the loader
will track additional metadata like the page number and text type (i.e. title, narrative text)
when that information is available.