Re: Typing, how come that :int is not ensuring int parameter?
On 12/06/20 9:32 AM, zljubi...@gmail.com wrote: OK, as I can see nothing is enforced but I can use mypy and tests for the purpose. Exactly! Well done - Python uses 'duck typing' and thus when the Typing module was added, it became an option. As mentioned elsewhere, it provides "hints" at 'compile time'. As I am using pycharm, looks like I need a plugin for mypy. There are two of them out there: non official: https://plugins.jetbrains.com/plugin/11086-mypy and official: https://plugins.jetbrains.com/plugin/13348-mypy-official- Do you have any experience with any of these plugins? Please share your opinion. I don't have a competent opinion for the current Pycharm, but hope that others will answer. TBH I'd be surprised if it doesn't come 'baked in'. -- Regards =dn -- https://mail.python.org/mailman/listinfo/python-list
Re: Typing, how come that :int is not ensuring int parameter?
OK, as I can see nothing is enforced but I can use mypy and tests for the purpose. As I am using pycharm, looks like I need a plugin for mypy. There are two of them out there: non official: https://plugins.jetbrains.com/plugin/11086-mypy and official: https://plugins.jetbrains.com/plugin/13348-mypy-official- Do you have any experience with any of these plugins? Please share your opinion. Best regards. -- https://mail.python.org/mailman/listinfo/python-list
Re: Typing, how come that :int is not ensuring int parameter?
On 12/06/20 8:51 AM, zljubi...@gmail.com wrote: Hi, If I run this code: class Property: def __init__(self, var: int): self.a: int = var @property def a(self): return self.__a @a.setter def a(self, var: int): if var > 0 and var % 2 == 0: self.__a = var else: self.__a = 2 if __name__ == '__main__': x = Property(1.5) print(x.a) I am getting 2. How come, if I have created a class with :int in order to ensure that "a" property must be an integer, that I can create an instance with float (1.5)? You may be confusing Python with some other programming language previously-learned. We need to 're-wire' the way your mind is working because whilst you are not-wrong for that-language, you are not-right for Python. So, I'm not going to answer your question directly, but to offer you a learning-path:- What did mypy (or...) say, when you ran tests against the source-code? (Typing is no use without such a testing regime!) Have you read the docs for Typing? - and for extra bonus-points, the numerous PEPs (proposals and accepted) related to how Python implements Typing? (that done, you will likely answer your own question, and accumulate some useful learning about Python - at both the practical and philosophical/idiomatic levels) -- Regards =dn -- https://mail.python.org/mailman/listinfo/python-list
Re: Typing, how come that :int is not ensuring int parameter?
> On 11 Jun 2020, at 21:51, zljubi...@gmail.com wrote: > > Hi, > > If I run this code: > class Property: > >def __init__(self, var: int): >self.a: int = var > >@property >def a(self): >return self.__a > >@a.setter >def a(self, var: int): >if var > 0 and var % 2 == 0: >self.__a = var >else: >self.__a = 2 > > if __name__ == '__main__': >x = Property(1.5) >print(x.a) > > I am getting 2. > How come, if I have created a class with :int in order to ensure that "a" > property must be an integer, that I can create an instance with float (1.5)? The : int is a type *hint* that isn not enforced by python. If you use a checker program like mypy it will use the type hints and report problems to your. You can install myy with pip. $ python3 -m pip install mypy I put your code in a.py and then checked it: $ /Library/Frameworks/Python.framework/Versions/3.8/bin/mypy a.py a.py:18: error: Argument 1 to "Property" has incompatible type "float"; expected "int" Found 1 error in 1 file (checked 1 source file) As you can see it found the problem. Barry > > Regards. > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Typing, how come that :int is not ensuring int parameter?
Hi, If I run this code: class Property: def __init__(self, var: int): self.a: int = var @property def a(self): return self.__a @a.setter def a(self, var: int): if var > 0 and var % 2 == 0: self.__a = var else: self.__a = 2 if __name__ == '__main__': x = Property(1.5) print(x.a) I am getting 2. How come, if I have created a class with :int in order to ensure that "a" property must be an integer, that I can create an instance with float (1.5)? Regards. -- https://mail.python.org/mailman/listinfo/python-list
