🔒 non-None assertion operator?

[kindred pier]

Im using python3.10 with type checking/hints - and sometimes the type checker fails to determine that the type is not None because of an earlier/complicated existance check.

Is there a syntax equivalent to typescripts non-null-assertion operator? eg doSomething(i_am_not_null!)

[wind fog]

@kindred pier

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[snow temple]

assert x is not None?

[gleaming mist]

(That's a statement tho)

[snow temple]

@kindred pier

Ooh, yeah

Umm

[kindred pier]

I know I can do a cast, but its so messy

[gleaming mist]

you can probably write a function for it

[snow temple]

You could always make your own typegaurd function if you really need to do a expression

[kindred pier]

from typing import cast

doSomething(cast(MyType, my_non_null_type))

[gleaming mist]

I was thinking put the assert in a function

[snow temple]

Idk if that would work with a checker though

[kindred pier]

we've already verified the type isn't None elsewhere

its just the type checker that fails to reaize it

[gleaming mist]

the assert function would basically be a cast

But you would not specify the type you want it to be which is easier

[kindred pier]

hmmm

[snow temple]

But to be honest I would always just:

assert i_am_not_null is not None  # we checked that it was not none above
do_something(i_am_not_null)

And if i_am_not_null is a function call or something, just assign it to a variable first

[wind fog]

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