Why do people think Python is ducktyped? The syntax is quite explicit, just because x = 5. is shorthand for x = float(5) doesn't mean it's doing weird mutations. The closest would be maybe that something like:

x = 5
y = 2.
z = x * y

works (I think) but that's not exactly a wacky behaviour. It's not like it ever does the wrong behaviour of casting a float to an int which can erase meaningful data and cause unpredictable behaviour.

I mean you can (and often should!) give functions/methods type signatures ffs.

[–] [email protected] 11 points 1 month ago* (last edited 1 month ago) (2 children)

Because to a certain extent Python is duck typed. Python has no concept of interfaces, unless you count the abc module combined with manual isinstance() checks, which I've never seen anyone do in production. In order to be passed to some function that expects a "file-like object", it just has to have methods named read(), seek(), and possibly isatty(). The Python philosophy, at least as I see it, is "as long as it has methods named walk() and quack(), it's close enough to a duck for me to treat it as one".

Duck typing is distinct from weak type systems, though.

[–] [email protected] 4 points 1 month ago

Python has Interfaces in the form of protocols, but those are explicitly duck-typed

[–] [email protected] 3 points 1 month ago (1 children)

Yeah I guess I should think before I say shit.

You're right.

[–] [email protected] 1 points 1 month ago (1 children)

Thank you for acknowledging that. I'd also like to say for the record that you were literally one word off from being correct.

[–] [email protected] 1 points 1 month ago (1 children)

In my head I had conflated duck and weak typing. I'm not an oop programmer (tbh I'm not much of a programmer to begin with) and since what Python does e.g. with file handles is closer to say in Haskell making a wrapper

DataStream x -> FileHandle x

Where like implementing the read/write/open etc methods are equivalent to implementing the function mappings.

Which is very different from say JS "Herr durr I'm going to cast an int to a string and then error" I assumed the latter was "duck typing"

[–] [email protected] 1 points 3 weeks ago* (last edited 3 weeks ago)

I don't know enough Haskell to tell you whether you're right about that or not (read: I know literally zero Haskell) but that sounds vaguely correct. That said, JavaScript is strongly and dynamically typed as well -- it's just a lot more lenient with implicit type conversions than Python is because of obscure 90s bullshit.

Also: don't let anyone tell you you're not a real programmer. If you even know what Haskell is, you've more than passed my bar.