4 ms·

AFAIK this doesn't imply static type checking though. The types are at best checked at runtime, aren't they? If so, it doesn't really help much.

icebraining 9y ago
No, it's static. You run the "mypy" command, which statically analyzes the Python code.
zeugmasyllepsis 9y ago
Mypy is a static type checker for Python. From the intro in the MyPy docs. MyPy is a legitimate static type checker for Python, with similar capabilities and limitations as other statically typed languages. There's an escape hatch to get you back to dynamic land (the `Any` type) and you can do naughty things at runtime if you use it (in the same way that you can in languages like C#), but using Mypy you can get decent type checking without actually running your program.
8fingerlouie 9y ago
It doesn't check runtime (AFAIK neither does Go, it checks compile time). In fact, Python fully ignores any type hints. When coupled with mypy (http://mypy-lang.org/ http://mypy-lang.org/) they can be used to do type checking at "compile time", and with DropBox's pyannotate (https://github.com/dropbox/pyannotate https://github.com/dropbox/pyannotate), they can even be auto generated for existing code. I'm not saying Python with type hints is better than a statically typed language, merely suggesting a possible solution if Python ends up being the preferred language. Personally i love Go for the things i've used it for, and i've written and maintained large code bases in Python, and hated every minute of it. The same can be said for large code bases i've written in C, or even Java. I've written kernels for GSM mobile phones, software for sortation devices (airport baggage sorters, mail sorters, etc), banking software, and despite our teams best intentions, given enough time and customization to meet customer demands, there is always some remote corner of the code that ends up as a "steaming pile"

icebraining 9y ago

No, it's static. You run the "mypy" command, which statically analyzes the Python code.

zeugmasyllepsis 9y ago

Mypy is a static type checker for Python. From the intro in the MyPy docs. MyPy is a legitimate static type checker for Python, with similar capabilities and limitations as other statically typed languages. There's an escape hatch to get you back to dynamic land (the `Any` type) and you can do naughty things at runtime if you use it (in the same way that you can in languages like C#), but using Mypy you can get decent type checking without actually running your program.

8fingerlouie 9y ago

It doesn't check runtime (AFAIK neither does Go, it checks compile time). In fact, Python fully ignores any type hints. When coupled with mypy (http://mypy-lang.org/ http://mypy-lang.org/) they can be used to do type checking at "compile time", and with DropBox's pyannotate (https://github.com/dropbox/pyannotate https://github.com/dropbox/pyannotate), they can even be auto generated for existing code. I'm not saying Python with type hints is better than a statically typed language, merely suggesting a possible solution if Python ends up being the preferred language. Personally i love Go for the things i've used it for, and i've written and maintained large code bases in Python, and hated every minute of it. The same can be said for large code bases i've written in C, or even Java. I've written kernels for GSM mobile phones, software for sortation devices (airport baggage sorters, mail sorters, etc), banking software, and despite our teams best intentions, given enough time and customization to meet customer demands, there is always some remote corner of the code that ends up as a "steaming pile"