mypy

---

The MyPy Python type checker (http://mypy-lang.org/).

Backend: pants.backend.python.typecheck.mypy

Config section: [mypy]

Basic options

args

--mypy-args="[<shell_str>, <shell_str>, ...]"
PANTS_MYPY_ARGS

pants.toml

[mypy]
args = [
    <shell_str>,
    <shell_str>,
    ...,
]

default: []

Arguments to pass directly to MyPy, e.g. --mypy-args='--python-version 3.7 --disallow-any-expr'.

export

--[no-]mypy-export
PANTS_MYPY_EXPORT

pants.toml

[mypy]
export = <bool>

default: True

If true, export a virtual environment with MyPy when running /home/josh/work/scie-pants/dist/pants export.

This can be useful, for example, with IDE integrations to point your editor to the tool's binary.

skip

--[no-]mypy-skip
PANTS_MYPY_SKIP

pants.toml

[mypy]
skip = <bool>

default: False

If true, don't use MyPy when running /home/josh/work/scie-pants/dist/pants check.

Advanced options

config

--mypy-config=<file_option>
PANTS_MYPY_CONFIG

pants.toml

[mypy]
config = <file_option>

default: None

Path to a config file understood by MyPy (https://mypy.readthedocs.io/en/stable/config_file.html).

Setting this option will disable [mypy].config_discovery. Use this option if the config is located in a non-standard location.

config_discovery

--[no-]mypy-config-discovery
PANTS_MYPY_CONFIG_DISCOVERY

pants.toml

[mypy]
config_discovery = <bool>

default: True

If true, Pants will include any relevant config files during runs (mypy.ini, .mypy.ini, and setup.cfg).

Use [mypy].config instead if your config is in a non-standard location.

console_script

--mypy-console-script=<str>
PANTS_MYPY_CONSOLE_SCRIPT

pants.toml

[mypy]
console_script = <str>

default: mypy

The console script for the tool. Using this option is generally preferable to (and mutually exclusive with) specifying an --entry-point since console script names have a higher expectation of staying stable across releases of the tool. Usually, you will not want to change this from the default.

entry_point

--mypy-entry-point=<str>
PANTS_MYPY_ENTRY_POINT

pants.toml

[mypy]
entry_point = <str>

default: None

The entry point for the tool. Generally you only want to use this option if the tool does not offer a --console-script (which this option is mutually exclusive with). Usually, you will not want to change this from the default.

extra_requirements

--mypy-extra-requirements="['<str>', '<str>', ...]"
PANTS_MYPY_EXTRA_REQUIREMENTS

pants.toml

[mypy]
extra_requirements = [
    '<str>',
    '<str>',
    ...,
]

default: []

Any additional requirement strings to use with the tool. This is useful if the tool allows you to install plugins or if you need to constrain a dependency to a certain version.

extra_type_stubs

--mypy-extra-type-stubs="['<str>', '<str>', ...]"
PANTS_MYPY_EXTRA_TYPE_STUBS

pants.toml

[mypy]
extra_type_stubs = [
    '<str>',
    '<str>',
    ...,
]

default: []

Extra type stub requirements to install when running MyPy.

Normally, type stubs can be installed as typical requirements, such as putting them in requirements.txt or using a python_requirement target. Alternatively, you can use this option so that the dependencies are solely used when running MyPy and are not runtime dependencies.

Expects a list of pip-style requirement strings, like ['types-requests==2.25.9'].

We recommend also enabling [mypy].extra_type_stubs_lockfile for a more reproducible build and less supply-chain security risk.

extra_type_stubs_lockfile

--mypy-extra-type-stubs-lockfile=<str>
PANTS_MYPY_EXTRA_TYPE_STUBS_LOCKFILE

pants.toml

[mypy]
extra_type_stubs_lockfile = <str>

default: <none>

Path to a lockfile for the option [mypy].extra_type_stubs.

Set to the string <none> to opt out of using a lockfile. We do not recommend this if you use [mypy].extra_type_stubs, though, as lockfiles are essential for reproducible builds and supply-chain security.

To use a lockfile, set this option to a file path relative to the build root, then run /home/josh/work/scie-pants/dist/pants generate-lockfiles --resolve=mypy-extra-type-stubs.

interpreter_constraints

--mypy-interpreter-constraints="['<str>', '<str>', ...]"
PANTS_MYPY_INTERPRETER_CONSTRAINTS

pants.toml

[mypy]
interpreter_constraints = [
    '<str>',
    '<str>',
    ...,
]

default:

[
  "CPython>=3.7,<4"
]

Python interpreter constraints for this tool.

lockfile

--mypy-lockfile=<str>
PANTS_MYPY_LOCKFILE

pants.toml

[mypy]
lockfile = <str>

default: <default>

Path to a lockfile used for installing the tool.

Set to the string <default> to use a lockfile provided by Pants, so long as you have not changed the --version and --extra-requirements options, and the tool's interpreter constraints are compatible with the default. Pants will error or warn if the lockfile is not compatible (controlled by [python].invalid_lockfile_behavior). See https://github.com/pantsbuild/pants/blob/release_2.14.2/src/python/pants/backend/python/typecheck/mypy/mypy.lock for the default lockfile contents.

Set to the string <none> to opt out of using a lockfile. We do not recommend this, though, as lockfiles are essential for reproducible builds and supply-chain security.

To use a custom lockfile, set this option to a file path relative to the build root, then run /home/josh/work/scie-pants/dist/pants generate-lockfiles --resolve=mypy.

Alternatively, you can set this option to the path to a custom lockfile using pip's requirements.txt-style, ideally with --hash. Set [python].invalid_lockfile_behavior = 'ignore' so that Pants does not complain about missing lockfile headers.

source_plugins

--mypy-source-plugins="[<target_option>, <target_option>, ...]"
PANTS_MYPY_SOURCE_PLUGINS

pants.toml

[mypy]
source_plugins = [
    <target_option>,
    <target_option>,
    ...,
]

default: []

An optional list of python_sources target addresses to load first-party plugins.

You must also set plugins = path.to.module in your mypy.ini, and set the [mypy].config option in your pants.toml.

To instead load third-party plugins, set the option [mypy].extra_requirements and set the plugins option in mypy.ini. Tip: it's often helpful to define a dedicated 'resolve' via [python].resolves for your MyPy plugins such as 'mypy-plugins' so that the third-party requirements used by your plugin, like mypy, do not mix with the rest of your project. Read that option's help message for more info on resolves.

version

--mypy-version=<str>
PANTS_MYPY_VERSION

pants.toml

[mypy]
version = <str>

default: mypy==0.961

Requirement string for the tool.

Deprecated options

None

Related subsystems

None