types-lxml-multi-subclass 2026.2.16
Complete lxml external type annotation
Requires Python: >=3.9
Keywords: lxml, typing, stubs, annotation

[![PyPI version](https://img.shields.io/pypi/v/types-lxml.svg)](https://pypi.org/project/types-lxml/)
![Supported Python](https://img.shields.io/python/required-version-toml?tomlFilePath=https%3A%2F%2Fraw.githubusercontent.com%2Fabelcheung%2Ftypes-lxml%2Fmain%2Fpyproject.toml
)
![Wheel](https://img.shields.io/pypi/wheel/types-lxml.svg)

## Important note

- Since `2026.02.16`:
  - Partial support of [`ty` type checker](https://docs.astral.sh/ty/)
  - Supports type checking under `PyPy` 3.11

- Since `2026.01.01`:
  - Support for [`pyrefly` type checker](https://pyrefly.org/)
  - New `mypy` plugin that mimics [`XMLParser.set_element_class_lookup()` behavior](https://github.com/abelcheung/types-lxml/wiki/Using-specialised-class-directly#no-automatic-change-of-subscript)

- Since `2025.11.25`:
  - [PEP 800 support](https://peps.python.org/pep-0800/), thus only compatible with newest type checkers as of Oct 2025
  - Declare and make use of Python 3.14 support; drops Python 3.8 support

- Since `2025.08.25`:
  - Supports `lxml` 6.0 and 5.4, while `lxml` 4.9 will not be tested anymore

- Since `2025.03.04`:
  - `BeautifulSoup4` package is added as dependency to utilise its inline annotation, thus dropping `types-beautifulsoup4` dependency.
  - Fixes compatibility with older versions of type checkers, as well as `mypy` 1.14+.


## Introduction

This repository contains [external type annotations](https://peps.python.org/pep-0561/) for [`lxml`](http://lxml.de/). It can be used by [type-checking tools](#goal---support-multiple-type-checkers) to check code that uses `lxml`, or used within IDEs like [Visual Studio Code](https://code.visualstudio.com/) to facilitate development.

## Goal ① : Completion

Implementation is complete since 1Q 2003, thus no more [considered as `partial`](https://peps.python.org/pep-0561/#partial-stub-packages). Following submodules intentionally not implemented due to irrelevance to type checking or other reasons:

  - `lxml.etree.Schematron` (obsolete and superseded by `lxml.isoschematron`)
  - `lxml.usedoctest` (for testing only)
  - `lxml.html.usedoctest` (for testing only)
  - `lxml.html.formfill` (shouldn't have existed, this would belong to HTTP libraries like `requests` or `httpx`)

## Goal ② : Support multiple type checkers

Currently the annotations are validated for following type checkers:

| Name | Version |
| --- | :-- |
| [`basedpyright`](https://github.com/DetachHead/basedpyright) | ≥ 1.31.6 |
| [`mypy`](https://github.com/python/mypy) | ≥ 1.18.1 |
| [`pyrefly`](https://pyrefly.org/) | ≥ 0.46.3 |
| [`pyright`](https://github.com/microsoft/pyright) | ≥ 1.1.406 |
| [`ty`](https://docs.astral.sh/ty/) | ≥ 0.0.7 |

`pyright` and `basedpyright` are recommended for their greater flexibility, maturity and early adoption of newer type checking features. In the future, there is plan to bring even more type checker support (such as `ty` or `zuban`).

## Goal ③: Review and test suite

- [x] All prior `lxml-stubs` contributions are reviewed thoroughly, bringing coherency of annotation across the whole package
- [x] Perform runtime check, and compare against static type checker result; this guarantees annotations are indeed working in real world, not just within some cooked up test suite
- [x] Existing static test suite already vastly expanded, and is under progress of migrating to runtime test
- [x] Modernize package building infrastructure

## Goal ④ : Geared towards users

#### Docstring

This package tries to bring type annotation specific docstrings for some classes and functions, explaining how they can be used. Following screenshot demonstrates annotation specific docstring in Visual Studio Code:

![Stub docstring in VSCode mouseover tooltip](https://user-images.githubusercontent.com/83110/277119481-debbd929-afbd-4f59-b9e6-52a1f7f23241.png)

#### Warnings for exception and wrong code

![image showing deprecation warning](https://github.com/user-attachments/assets/6ab30a54-60e7-4e34-932a-2ac2e253c669)

`pyright` and `basedpyright` users receive additional benefit of being forewarned when their lxml code will likely cause undesirable runtime behavior or outright exception.
- [#64](https://github.com/abelcheung/types-lxml/issues/64) covers one such example where such warnings are warrented.
- Another example is `html.html5parser` submodule functions causing exception when `str` input and `guess_charset` parameter are used together.

Similarly their corresponding Visual Studio Code extensions would display visual cue when such problematic usage is encountered, as shown in above screenshot.

> [!NOTE]
> This feature makes use of [`@deprecated` decorator](https://typing.python.org/en/latest/spec/directives.html#deprecated) from Python 3.13. `mypy` disables such warnings by default, and need to be [turned on explicitly](https://mypy.readthedocs.io/en/stable/error_code_list2.html#check-that-imported-or-used-feature-is-deprecated-deprecated).

#### Class inheritance change

Current annotations are geared towards convenience for programmers' convenience instead of absolute logical 'correctness'. The [deviation of class inheritance](https://github.com/abelcheung/types-lxml/wiki/Element-inheritance-change) for `HtmlComment` and friends is one prominent example.

----

## Installation

The normal choice for most people is to fetch package from PyPI, like:

    uv pip install -U types-lxml  # using uv
    pip install -U types-lxml  # using pip

In the unlikely case PyPI is down, one can directly download wheel from [latest release in GitHub](https://github.com/abelcheung/types-lxml/releases/latest), and then perform installation as local file.

As convenience, it is possible to [pull development related packages](https://peps.python.org/pep-0508/#extras). This helps when you want to submit PR on bugs or features:

    uv pip install -U types-lxml[dev]
    pip install -U types-lxml[dev]

The stub package supports all Python versions since 3.9. But if you want to create PR and test your changes, Python 3.10 is needed.

### Mypy plugin usage

Mypy plugin bundled with this stub package needs to be explicitly turned on from config. Add these two lines under `[mypy]` global section if you're using INI file:

```ini
plugins =
    mypy_plugin_lxml.main
```

Alternatively, add this under `[tool.mypy]` section for `pyproject.toml`:

```toml
plugins = ["mypy_plugin_lxml.main"]
```

### Choosing the build

Since `2024.08.07` release, there will be two versions of `types-lxml`. First one is the default one; if there's no problem using it, there's no need to switch.

The second version, `types-lxml-multi-subclass`, is intended for specific need, namely creation of multiple lxml element subclasses. For example:

```mermaid
  graph TD;
      etree.ElementBase-->MyBaseElement;
      MyBaseElement-->MySubElement1;
      MyBaseElement-->MySubElement2;
```

If a parsed or constructed element tree consists of single type of element nodes, it is safe to assume the children or parent of a node are of the same type too. But this assumption does not hold for multiple subclasses. Using diagram above as example, calling `.iter()` method from `MyBaseElement` node may produce element of any subelement or even `MyBaseElement` itself.
Therefore output type should be simply `MyBaseElement` only.

Such scenario is already in effect for `lxml.html`. `<form>` element (`FormElement`) is supposed to contain other form related tags like `<input>`, `<select>` etc. But we can't possibly pinpoint single subelement type, so `<form>` children can only possibly be of type `HtmlElement`. The multiple subelement scenario is already hardcoded for `HtmlElement` and `ObjectifiedElement` within this annotation package, but users may choose to have their own overridden element subclasses (inherit from `ElementBase`) too.

The 2 paradigms can't coexist within a single type annotation package. See [bug #51](https://github.com/abelcheung/types-lxml/issues/51) that illustrated why multiple build is necessary.

> [!IMPORTANT]
> Users can only choose to install either build, not both. `pip` would [arbitrarily overwrite conflicting files with one another](https://github.com/pypa/pip/issues/4625). If in doubt, removing existing package first, then install the one you needed.


### Release file attestation

> [!TIP]
> For those haven't heard of it, this is sort of like `gnupg` or [`minisign`](https://jedisct1.github.io/minisign/) signatures, but with GitHub backed infrastructure.

Since `2024.11.08` users can download `types-lxml` release files and verify that they indeed do originate from GitHub. After downloading release wheel file (say `pip download types-lxml`, or browser access to PyPI directly), one can use [GitHub cli](https://cli.github.com/) to verify it comes from this GitHub repository without being altered:

```
gh at verify types_lxml-2024.11.8-py3-none-any.whl --repo abelcheung/types-lxml
```

Should generate following result:

```
Loaded digest sha256:4b4fa7f9e2f1d5f58b98ac9852a75927e4e0f69363249f9cebc78db095c046e0 for file://types_lxml-2024.11.8-py3-none-any.whl
Loaded 1 attestation from GitHub API
✓ Verification succeeded!

sha256:4b4fa7f9e2f1d5f58b98ac9852a75927e4e0f69363249f9cebc78db095c046e0 was attested by:
REPO                   PREDICATE_TYPE                  WORKFLOW
abelcheung/types-lxml  https://slsa.dev/provenance/v1  .github/workflows/release.yml@refs/tags/2024.11.08
```


## History

Type annotations for `lxml` were initially included in [typeshed](https://www.github.com/python/typeshed), but as it was still incomplete at that time, the stubs are [ripped out as a separate project](https://github.com/python/typeshed/issues/525). The code was since then under governance of lxml, until 2022 when this fork intended to revamp `lxml-stubs` completely and emerge into separate project.

`types-lxml` is a fork of `lxml-stubs` that strives for the goals described above, so that most people would find it more useful.