Pass arguments by reference in Python

Pass arguments by reference—in Python!
byref
is a decorator that allows Python functions to declare reference parameters, with similar semantics to C++’s T&
or C#’s ref T
. Any modifications made within the function to these parameters will be picked up by the caller.
Usage
from byref import byref
@byref("x")
def add(x, y, /):
x += y
a = 60
add(a, 40)
print(f"{a}!") # this prints 100!
Motivation
I thought it would be funny.