Neither readability package is installed. Run `python -m pip install readability-lxml` (the real article extractor). Make sure you do NOT install the unrelated bare `readability` package, or you will trade this error for the `cannot import name 'Document'` one.

## The error

```text
ImportError: No module named 'readability'
```

## Fix it

1. **Install readability-lxml**

```
python -m pip install readability-lxml
```
Expected: `Successfully installed readability-lxml-...`.

2. **Confirm**

```
python -c "from readability import Document; print('ok')"
```
Expected: prints `ok`.

## When this applies

- the error is `No module named 'readability'` (nothing installed)
- a fresh env for an article-extraction script

## When it does NOT apply

- `cannot import name 'Document' from 'readability'` means the WRONG package is installed
- `partially initialized module` means your own file shadows it

## Compatibility

readability-lxml 0.8.x. (On Python 2 this printed as ImportError; on Python 3.6+ the same situation usually prints ModuleNotFoundError. Both wordings mean the same missing install.)

## Why it happens

The package was never installed into the active interpreter. The extra trap here is installing the wrong PyPI name afterward, so the fix spells out readability-lxml explicitly.

## Edge cases

- readability-lxml needs lxml. If the install succeeds but the import then fails on lxml, fix lxml separately.