Adding Overloads of stdlib Built-in Types __new__ with No Arguments

[matthewyu0311]

Calling int() and str() with no arguments returns 0 and "" respectively, likewise for bool() == False and bytes() == b"". But to actually call these constructors without arguments is very unusual and is likely a mistake on part of the user.

# a and b are two strings
x = int(a)
y = int()    # typo, should be int(b)

x / y    # ZeroDivisionError

It will be helpful for type stubs to denote that such no-argument calls return a constant value, and for IDEs to possibly notify of such use.

Currently the stub for int.__new__ looks like this:

typeshed/stdlib/builtins.pyi

Line 257 in 904ea9e

def __new__(cls, x: ConvertibleToInt = 0, /) -> Self: ...

class int:
    @overload
    def __new__(cls, x: ConvertibleToInt = 0, /) -> Self: ...

and str.__new__:

class str(Sequence[str]):
    @overload
    def __new__(cls, object: object = "") -> Self: ...

I suggest adding an overload with no argument and removing the default parameter value from the one-arg __new__, though I'm not sure if there are existing special behaviors of type checkers regarding builtins that I'm unaware of.

[srittau]

This makes sense to me. At least an exploratory PR would be welcome.

[AlexWaygood]

previously discussed in #6069 (the title mentions bool but the discussion covered other builtin types too). The exploratory PR is at #10465