Public API for for building wheels.

## py_package

py_package(name, deps, packages)

A rule to select all files in transitive dependencies of deps which
belong to given set of Python packages.

This rule is intended to be used as data dependency to py_wheel rule.

**ATTRIBUTES**

| Name  | Description | Type | Mandatory | Default |
| :------------- | :------------- | :------------- | :------------- | :------------- |
| name |  A unique name for this target.   | Name (https://bazel.build/concepts/labels#target-names) | required |  |
| deps |  -   | List of labels (https://bazel.build/concepts/labels) | optional | [] |
| packages |  List of Python packages to include in the distribution. Sub-packages are automatically included.   | List of strings | optional | [] |

## py_wheel_dist

py_wheel_dist(name, out, wheel)

Prepare a dist/ folder, following Python's packaging standard practice.

See https://packaging.python.org/en/latest/tutorials/packaging-projects/#generating-distribution-archives
which recommends a dist/ folder containing the wheel file(s), source distributions, etc.

This also has the advantage that stamping information is included in the wheel's filename.

**ATTRIBUTES**

| Name  | Description | Type | Mandatory | Default |
| :------------- | :------------- | :------------- | :------------- | :------------- |
| name |  A unique name for this target.   | Name (https://bazel.build/concepts/labels#target-names) | required |  |
| out |  name of the resulting directory   | String | required |  |
| wheel |  a [py_wheel rule](/docs/packaging.md#py_wheel_rule)   | Label (https://bazel.build/concepts/labels) | optional | None |

## py_wheel_rule

py_wheel_rule(name, abi, author, author_email, classifiers, console_scripts, deps, description_file,
              distribution, entry_points, extra_distinfo_files, extra_requires, homepage, license,
              platform, python_requires, python_tag, requires, stamp, strip_path_prefixes, version)

Internal rule used by the [py_wheel macro](/docs/packaging.md#py_wheel).

These intentionally have the same name to avoid sharp edges with Bazel macros.
For example, a `bazel query` for a user's `py_wheel` macro expands to `py_wheel` targets,
in the way they expect.

**ATTRIBUTES**

| Name  | Description | Type | Mandatory | Default |
| :------------- | :------------- | :------------- | :------------- | :------------- |
| name |  A unique name for this target.   | Name (https://bazel.build/concepts/labels#target-names) | required |  |
| abi |  Python ABI tag. 'none' for pure-Python wheels.   | String | optional | "none" |
| author |  A string specifying the author of the package.   | String | optional | "" |
| author_email |  A string specifying the email address of the package author.   | String | optional | "" |
| classifiers |  A list of strings describing the categories for the package. For valid classifiers see https://pypi.org/classifiers   | List of strings | optional | [] |
| console_scripts |  Deprecated console_script entry points, e.g. {'main': 'examples.wheel.main:main'}.

Deprecated: prefer the entry_points attribute, which supports console_scripts as well as other entry points.   | Dictionary: String -> String (https://bazel.build/rules/lib/dict) | optional | {} |
| deps |  Targets to be included in the distribution.

The targets to package are usually py_library rules or filesets (for packaging data files).

Note it's usually better to package py_library targets and use entry_points attribute to specify console_scripts than to package py_binary rules. py_binary targets would wrap a executable script that tries to locate .runfiles directory which is not packaged in the wheel.   | List of labels (https://bazel.build/concepts/labels) | optional | [] |
| description_file |  A file containing text describing the package.   | Label (https://bazel.build/concepts/labels) | optional | None |
| distribution |  Name of the distribution.

This should match the project name onm PyPI. It's also the name that is used to refer to the package in other packages' dependencies.   | String | required |  |
| entry_points |  entry_points, e.g. {'console_scripts': ['main = examples.wheel.main:main']}.   | Dictionary: String -> List of strings (https://bazel.build/rules/lib/dict) | optional | {} |
| extra_distinfo_files |  Extra files to add to distinfo directory in the archive.   | Dictionary: Label -> String (https://bazel.build/rules/lib/dict) | optional | {} |
| extra_requires |  List of optional requirements for this package   | Dictionary: String -> List of strings (https://bazel.build/rules/lib/dict) | optional | {} |
| homepage |  A string specifying the URL for the package homepage.   | String | optional | "" |
| license |  A string specifying the license of the package.   | String | optional | "" |
| platform |  Supported platform. Use 'any' for pure-Python wheel.

If you have included platform-specific data, such as a .pyd or .so extension module, you will need to specify the platform in standard pip format. If you support multiple platforms, you can define platform constraints, then use a select() to specify the appropriate specifier, eg:

 platform = select({     "//platforms:windows_x86_64": "win_amd64",     "//platforms:macos_x86_64": "macosx_10_7_x86_64",     "//platforms:linux_x86_64": "manylinux2014_x86_64", })    | String | optional | "any" |
| python_requires |  Python versions required by this distribution, e.g. '>=3.5,<3.7'   | String | optional | "" |
| python_tag |  Supported Python version(s), eg py3, cp35.cp36, etc   | String | optional | "py3" |
| requires |  List of requirements for this package. See the section on [Declaring required dependency](https://setuptools.readthedocs.io/en/latest/userguide/dependency_management.html#declaring-dependencies) for details and examples of the format of this argument.   | List of strings | optional | [] |
| stamp |  Whether to encode build information into the wheel. Possible values:

- stamp = 1: Always stamp the build information into the wheel, even in [--nostamp](https://docs.bazel.build/versions/main/user-manual.html#flag--stamp) builds. This setting should be avoided, since it potentially kills remote caching for the target and any downstream actions that depend on it.

- stamp = 0: Always replace build information by constant values. This gives good build result caching.

- stamp = -1: Embedding of build information is controlled by the [--[no]stamp](https://docs.bazel.build/versions/main/user-manual.html#flag--stamp) flag.

Stamped targets are not rebuilt unless their dependencies change.   | Integer | optional | -1 |
| strip_path_prefixes |  path prefixes to strip from files added to the generated package   | List of strings | optional | [] |
| version |  Version number of the package.

Note that this attribute supports stamp format strings as well as 'make variables'. For example:   - version = "1.2.3-{BUILD_TIMESTAMP}"   - version = "{BUILD_EMBED_LABEL}"   - version = "$(VERSION)"

Note that Bazel's output filename cannot include the stamp information, as outputs must be known during the analysis phase and the stamp data is available only during the action execution.

The [py_wheel](/docs/packaging.md#py_wheel) macro produces a .dist-suffix target which creates a dist/ folder containing the wheel with the stamped name, suitable for publishing.

See [py_wheel_dist](/docs/packaging.md#py_wheel_dist) for more info.   | String | required |  |

## PyWheelInfo

PyWheelInfo(name_file, wheel)

Information about a wheel produced by `py_wheel`

**FIELDS**

| Name  | Description |
| :------------- | :------------- |
| name_file |  File: A file containing the canonical name of the wheel (after stamping, if enabled).    |
| wheel |  File: The wheel file itself.    |

## py_wheel

py_wheel(name, twine, kwargs)

Builds a Python Wheel.

Wheels are Python distribution format defined in https://www.python.org/dev/peps/pep-0427/.

This macro packages a set of targets into a single wheel.
It wraps the [py_wheel rule](#py_wheel_rule).

Currently only pure-python wheels are supported.

Examples:

```python
# Package some specific py_library targets, without their dependencies
py_wheel(
    name = "minimal_with_py_library",
    # Package data. We're building "example_minimal_library-0.0.1-py3-none-any.whl"
    distribution = "example_minimal_library",
    python_tag = "py3",
    version = "0.0.1",
    deps = [
        "//examples/wheel/lib:module_with_data",
        "//examples/wheel/lib:simple_module",
    ],
)

# Use py_package to collect all transitive dependencies of a target,
# selecting just the files within a specific python package.
py_package(
    name = "example_pkg",
    # Only include these Python packages.
    packages = ["examples.wheel"],
    deps = [":main"],
)

py_wheel(
    name = "minimal_with_py_package",
    # Package data. We're building "example_minimal_package-0.0.1-py3-none-any.whl"
    distribution = "example_minimal_package",
    python_tag = "py3",
    version = "0.0.1",
    deps = [":example_pkg"],
)
```

To publish the wheel to Pypi, the twine package is required.
rules_python doesn't provide twine itself, see https://github.com/bazelbuild/rules_python/issues/1016
However you can install it with pip_parse, just like we do in the WORKSPACE file in rules_python.

Once you've installed twine, you can pass its label to the `twine` attribute of this macro,
to get a "[name].publish" target.

Example:

```python
py_wheel(
    name = "my_wheel",
    twine = "@publish_deps_twine//:pkg",
    ...
)
```

Now you can run a command like the following, which publishes to https://test.pypi.org/

```sh
% TWINE_USERNAME=__token__ TWINE_PASSWORD=pypi-*** \
    bazel run --stamp --embed_label=1.2.4 -- \
    //path/to:my_wheel.publish --repository testpypi
```


**PARAMETERS**

| Name  | Description | Default Value |
| :------------- | :------------- | :------------- |
| name |  A unique name for this target.   |  none |
| twine |  A label of the external location of the py_library target for twine   |  None |
| kwargs |  other named parameters passed to the underlying [py_wheel rule](#py_wheel_rule)   |  none |

