Variables `Final` by default (`mutable` / `var`)

[KotlinIsland]

a = 1
a = 2  # should be an error imo

a: var = 1
a = 2  # yeah, that's ok

[KotlinIsland]

mut? what is this, rust?

[KotlinIsland]

mut? what is this, rust?

good point, DetachHead said that mutable would be better, as it would scare people off from using it :DDDDD

[KotlinIsland]

what about:

a: mutable = [1,2,3]
a = []  # error
a[0] = 2  # ok

b: var = [1,2,3]
b = []  # ok
b[0] = 2  # error

c: var[mutable] = [1,2,3]
c = []  # ok
c[0] = 2  # ok

[KotlinIsland]

https://github.com/KotlinIsland/basedmypy/issues/45

[Zeckie]

This issue has a few examples, but not much explanation.

• Is this proposing a change to python itself, or just requiring every variable to have a type annotation?
• Is it trying to solve a particular issue (eg. in the first example is a's type Literal[1] or int?)
• What are var and mutable? new types?
• Is #189 a duplicate of this issue?

[KotlinIsland]

• Is this proposing a change to python itself, or just requiring every variable to have a type annotation?

This is only a feature within basedmypy.

• Is it trying to solve a particular issue (eg. in the first example is a's type Literal[1] or int?)

It's solving the issue of reassignable variables being the default option

• What are var and mutable? new types?

Potentially

• Is #189 a duplicate of this issue?

Similar, but is referring to final and is unrelated to Final

[DetachHead]

Similar, but is referring to final and is unrelated to Final

what is final

[KotlinIsland]

typing.final

[Zeckie]

So this issue is for variables, #189 is for methods?