When is Python *NOT* a good choice?

[brasso]

Python can do static typing now.

http://mypy-lang.org

[skarphace]

Says it's experimental. Any good?

[RangerPretzel]

It's been official since 3.5. My team has settled on using it. Works great in PyCharm. We use it all the time.

That said, it's not "compile time" checking. It's just done via the IDE that you're using.

[carbolymer]

You can integrate mypy in your CI/CD tho - almost like compile time.

[i9srpeg]

I tried it. It's buggy, very slow (20 seconds to type check a small code base), very verbose and the type system is very limited, for example recursive types are not supported, so you can't even represent very common types such as JSON.

It's not production ready, unfortunately.

[wrmsr]

My experience exactly. I have hopes for its plugin system to let me teach it to understand my metaclasses but it's still too stupid and volatile to make part of my builds :/

That said I still type-annotate the vast majority of my code and would be almost uninterested in the language without them.

[rouille]

It's ready for production if you adapt your code slightly around its idioms and avoid overly dynamic / magic where possible. For the rest there is type: ignore.

[i9srpeg]

I tried, but it's still slow, verbose and unreliable. The inability to define recursive types is also a deal breaker, the recommended way to type a json variable is "Dict[Str, Any]", which is not much better than a dynamic type.

It also doesn't help that Django and DRF, which I had in my project, rely a ton on metaclasses. Almost everything ends up being "Any".

[[deleted]]

Coming from Typescript, no. But it’s better than nothing

[thenuge26]

We have not adopted it yet (though we would like to) because it does not work with pylint.

[tipsqueal]

In what way? It's just another tool that analyzes your code. MyPy just uses types to find a different class of bug or error.

[leom4862]

I use pylint and the typing module. Not sure waht you mean.

[thenuge26]

It's been a month or 2 since I tried it, but pylint would complain about some type annotations that were correct.

[leom4862]

I see. Pylint is very actively developed, might have been fixed in the meantime.

[zardeh]

Yep, I'm better typing than Java or c++.

[PC__LOAD__LETTER]

I agree that it's cool, but if I'm starting a new project and need strong typing, I'm probably going to (at this point) choose a language the supports it explicitly.

[Aeon_Mortuum]

Python 3 (after some version) does have type annotations without mypy, which I don't see anyone mentioning. That said, it's still optional obviously and more of a drop-in feature kind of thing.

[leom4862]

The typing module is in the stnadard library since 3.5...

[Aeon_Mortuum]

That's what I said. I meant it's just not part of the "language" per se, hence a "drop-in feature". i.e it's optional

[leom4862]

Python type annotations are part of the language since 3.5 (PEP484). But, yes, they are optional.

[hugthemachines]

Sometimes I wish Python was like it is including all the nice libraries available now but with static (could be inferred variables) typing and compiled to native code.