matchawine/python-enforce-typing

An easy to use decorator to enforce static typing for function and dataclasses.

Adds a simple decorator enforce_types that enables enforcing strict typing on a function or dataclass using annotations.

Works with collection types and subtypes for example Dict[str, Tuple[int, int]], and with special types as Optional and Any.

Seeing as this uses type annotations from PEP 484, >=Python 3.5 is required.

PyPi project page: https://pypi.org/project/enforce-typing/

Heavily inspired from this SO post so credit goes mostly to him.

Installation

Other than downloading from PyPi with pip, you may also clone the repository and run the usual setuptools process:

$> git clone https://github.com/matchawine/python-enforce-typing.git && cd python-enforce-typing
$> python setup.py {build,install}

Usage

from typing import Any, Union, Optional
from dataclasses import dataclass
from enforce_typing import enforce_types

@enforce_types
@dataclass(frozen=True)
class Toto(object):
    this_or_that: Union[str, int]
    anything: Any
    name: str = ""
    value: int = 1
    maybe_not: Optional[bool] = None

>>> Toto(this_or_that=list(), anything=2)
TypeError: Expected type 'typing.Union[str, int]' for attribute 'this_or_that' but received type '<class 'list'>')

>>> Toto(this_or_that=1, anything=2, maybe_not=0)
TypeError: Expected type 'typing.Union[bool, NoneType]' for attribute 'maybe_not' but received type '<class 'int'>')

>>> Toto(this_or_that=1, anything=2, name=3)
TypeError: Expected type '<class 'str'>' for attribute 'name' but received type '<class 'int'>')

>>> Toto(this_or_that=1, anything=2, value=3.0)
TypeError: Expected type '<class 'int'>' for attribute 'value' but received type '<class 'float'>')

>>> Toto(this_or_that=1, anything=2)
Toto(this_or_that=1, anything=2, name='', value=1, maybe_not=None)

>>> Toto(this_or_that="titi", anything=list(), maybe_not=False)
Toto(this_or_that='titi', anything=[], name='', value=1, maybe_not=False)