A dynamic, runtime type checker for Python 3.7+!
>>> import runchecker
>>> @runchecker.check
... def hey_there(name: str, greeting: str) -> str:
... return greeting + " " + name + "!"
...
>>> hey_there("John", "Hello")
"Hello John!"
>>> hey_there(487, "Hello")
Traceback (most recent call last):
...
runchecker.errors.InvalidParameter: Parameter name with value 487 (type int) is incompatible with str!runchecker currently supports the following type hints:
- object
- Any
- None
- collections.abc.Mapping
- collections.abc.Sequence
- tuple
- Union
- Generic
- TypedDict
- Literal
- Annotated
runchecker plans to support the following type hints in the future:
- TypeVar
- Forward References
- and more to come!
If you have a custom Generic class that doesn't follow any of the protocols runchecker currently supports, no problem!
runchecker allows you to make a custom validator for your custom Generic class. Instance checks will already be done for you automatically.
All you have to do is inherit from runchecker.Validator, which is a protocol class that defines a dunder function (not method) called __validate__.
__validate__ takes in two parameters: the type_hint (typed as Any) and the value (typed as Any). The type_hint will be the type hint that called this validator, and the value will be the value to validate.
__validate__ has a return type of anything. All you have to do in your __validate__ implementation is raise runchecker.WrongType if the value parameter violates type_hint!
runchecker is licensed under the MIT License. Read the LICENSE file for more information.