strongly-typed 1.0.1.post3

Python module to enforce strong typing

strongly_typed

This is a python decorator that allows you to type-check functions. Itll check the type signature of the function and, if the signature and the parameters given mismatch, will raise an exception.

Inspiration

I wanted to use this to make sure that software i was going to write was resilient for data integrity reasons. I've also learned a lot about decorators, etc.

Usage

from strongly_typed import strongly_typed
@strongly_typed
def add(a: int, b: int, message_template: str):
    result = a + b
    message = message_template % result
    return message

add(1, 2, "The answer is %s!")
add(1, "e", 5) # raises an exception!

Known issues

• *args and **kwargs are not tested at all. This is because I'm not sure how I'd implement that. (Plus, I don't think it's very common to annotate those.)

• Using "interchangeable" types (e.g. using an int when a float is required, or vice versa) will raise an exception. This is by design. The whole idea is to prevent python's weak typing from screwing things up. Type coercion isn't the only way it can do that, but it's one of them - and not always caught by linters.

• Subclasses are not checked. So:

class Hello:
    def hi(self):
        print("hi")

class Subclass(Hello):
    def __init__(self):
        print("Init!")

@strongly_typed.strongly_typed
def run_hi(cls: Hello):
    cls.hi()

run_hi(Hello()) # OK
run_hi(Subclass()) # Raises TypeError

There may be an optional feature to check if it's a subclass, rather than the absolute type. That's not a thing yet, though.

Contributing

The code is probably terrible. Please help me fix it! If you have any suggestions, please let me know.

Licence

Copyright 2023 TheTechRobo Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.